新东方背诵50篇（含中文翻译）后30篇

>21 The Origin of SportsWhen did sport begin? If sport is, in essence, play, the claim might be made that sport is much older than    humankind, for, as we all have observed, the beasts play. Dogs and cats wrestle and play ball games. Fishes and    birds dance. The apes have simple, pleasurable games. Frolicking infants, school children playing tag, and adult        arm wrestlers are demonstrating strong, transgenerational and transspecies bonds with the universe of animals -    past, present, and future. Young animals, particularly, tumble, chase, run, wrestle, mock, imitate, and laugh(or so it seems) to the point of delighted exhaustion. Their play, and ours, appears to serve no other purpose than to    give pleasure to the players, and apparently, to remove us temporarily from the anguish of life in earnest.    Some philosophers have claimed that our playfulness is the most noble part of our basic nature. In their generous    conceptions, play harmlessly and experimentally permits us to put our creative forces, fantasy, and imagination    into action. Play is release from the tedious battles against scarcity and decline which are the incessant, and        inevitable, tragedies of life. This is a grand conception that excites and provokes. The holders of this view claim that the origins of our highest accomplishments - liturgy, literature, and law    - can be traced to a play impulse which, paradoxically, we see most purely enjoyed by young beasts and children. Our sports, in this rather happy,   nonfatalistic view of human nature, are more splendid creations of the nondatable, transspecies play impulse.体育的起源 体育运动开始于何时?如果体育运动的本质就是游戏的话，我们就可以宣称体育运动比人类古老，因为正如我们所观察到的，野兽也进行嬉戏。 狗和猫会扭抱玩球，鱼和鸟翩翩 起舞，猿类会进行一些简单的、愉快的游戏。 雀跃的幼儿，捉迷藏的学童和成年摔跤者展 示出人与动物界的有力的跨越世代与物种的永恒的联系--特别是幼兽，它们翻筋斗、追逐、 奔跑、扭打、模仿、嬉笑(或者看起来是)，直到愉快地精疲力尽。 他们的玩耍，同我们的 一样，似乎并没有别的目的而只是给游戏者以愉悦，暂时把我们从严肃生活的痛苦中拉出来。 一些哲学家称我们的嬉戏是我们本质中最崇高的部分。 依他们这些随意性很大的见解，游 戏无害而且实验性地允许我们的创造力、幻想和想象发挥作用。 游戏让人们从永不间断亦 不可避免的生活悲剧-与乏匮和衰退进行的枯燥抗争中得到一种解脱。 这是一个令人兴奋、 给人启发的伟大见解。 这种见解的持有者宣称，我们的最高成就如宗教典礼、文学、法律 的起源可以追溯到游戏的冲动。 但令人不解的是我们看到只有幼兽和小孩子才最纯粹地享 受着这种冲动。 从这种比较豁达和非宿命的人性观来看，我们的运动是超时代、跨物种的 辉煌的创造。>22 CollectiblesCollectibles have been a part of almost every culture since ancient times. Whereas some objects have been collected for their usefulness, others have been selected for their aesthetic beauty alone. In the United States, the kinds   of collectibles currently popular range fromtraditional objects such as stamps, coins, rare books, and art to more recent items of interest like dolls, bottles, baseball cards, and comic books.Interest in collectibles has increased enormously during the past decade, in part because some collectibles have   demonstrated their value as investments. Especially during cycles of high inflation, investors try to purchase        tangibles that will at least retain their current market values. In general, the most traditional collectibles will be sought because they have preserved their value over the years, there is an organized auction market for them,    and they are most easily sold in the event that cash is needed. Some examples of the most stable collectibles are    old masters, Chinese ceramics, stamps, coins, rare books, antique jewelry, silver, porcelain, art by well-known artists, autographs, and   period furniture. Other   items of more recent   interest include old photograph records, old    magazines, post cards, baseball cards, art glass, dolls, classic cars, old bottles, and comic books. These    relatively new kinds of collectibles may actually appreciate faster as short-term investments, but may not hold    their value as long-term investments. Once a collectible has had its initial play, it appreciates at a fairly steady rate, supported by an increasing number of enthusiastic collectors competing for the limited supply of    collectibles that become increasingly more difficult to locate.收藏品从古代开始，收藏品就是文化的一部分。 一些物品因它们的有用性被收藏，而另一些 则纯粹因为它们的美被收藏。 在美国，当今流行的收藏品种类从传统物件，如邮票、硬币、 珍本书籍、艺术品，到更近期一些的有趣的东西，如布娃娃、瓶子、垒球卡、连环漫画册。 对收藏品的兴趣在过去十年中大大地增长，部分原因是一些收藏品显示出了它们的投资价 值。 尤其在高通货膨胀时期，投资者尽量购买那些至少会保持他们现有市场价值的有形资 产。 一般来说，最传统的收藏品受青睐，因为它们多年后仍保持其价值。 它们拥有完善的 拍卖市场，在需要现金的时候最容易被卖掉。 一些最稳当的收藏品是古老的画作、中国陶 器、邮票、硬币、珍本书籍、古代珠宝、银器、瓷器、著名艺术家的作品、亲笔签名和有时 代特征的家具。 其它更近期的物品有旧唱片、旧杂志、明信片、垒球卡片、彩色玻璃、布 娃娃、早期汽车、古瓶和连环画册。 作为短期投资这些相对说来较新颖的收藏品的确可能 更快地增值，但作为长期投资则可能不能保值。 一旦一件收藏品有了它第一次交易，它便 以一个相当稳定的比率增值，这个增值率受到越来越多的热情的收藏者的支持，他们为有限 的而且越来越难找到的收藏品而竞争。>23 Henry FordAlthough Henry Ford's name is closely associated with the concept of mass production, he should receive equal   credit for introducing labor practices as early as 1913 that would be considered advanced even by today's    standards. Safety measures were improved, and the work day was reduced to eight hours, compared with the ten-or    twelve-hour day common at the time. In order to accommodate the shorter work day, the entire factory was converted    from two to three shifts.In addition, sick leaves as well as improved medical care for those injured on the job were instituted. The Ford    Motor Company was one of the first factories to develop a technical school to train specialized skilled laborers    and an English language school for immigrants. Some efforts were even made to hire the handicapped and provide jobs for former convicts.The most widely acclaimed innovation was the five-dollar-a-day minimum wage that was offered in order to recruit    and retain the best mechanics and to discourage the growth of labor unions. Ford explained the new wage policy in    terms of efficiency and profit sharing. He also mentioned the fact that his employees would be able to purchase the automobiles that they produced -- in effect creating a market for the product. In order to qualify for the minimum    wage, an employee had to establish a decent home and demonstrate good personal habits, including sobriety,    thriftiness, industriousness, and dependability. Although some criticism was directed at Ford for involving himself too much in the personal lives of his employees, there can be no doubt that, at a time when immigrants were being    taken advantage of in frightful ways, Henry Ford was helping many people to establish themselves in America.亨利?福特 尽管亨利?福特的名字和大生产的概念相连，但他在劳工保护上得到同样的赞誉，因为他早在 1913 年便实行了用今天的标准来衡量依然是先进的标准。 安全措施得到改进，日工 作时间从当时普遍的 10 或 12 小时减少到 8 小时。 为了适应更短的日工作时间，整个工厂 从双班变成了三班。而且，病假和改善了的工伤医疗得以制度化。 福特汽车公司是最早建 立技术学校来培训专门技工和为移民开设英语学校的工厂之一。 公司甚至为雇佣残疾人和 有前科的人而作出了一些努力。最受广泛称赞的革新是实行五美元一天的最低工资。 其目 的是招收和留住那些最好的技工并阻碍工会的发展。 福特从效率和利润分享的角度来解释 这项新的工资政策。 他也提到这样一个事实，他的员工可以买他们生产的汽车--这实际上 是为其产品另开辟了一个市场。 为了够资格得到最低工资，员工必须建立一个得体的家庭 并显示出良好的个人习惯，包括节制、俭省、勤勉和可靠。 虽然有人批评福特过多地干涉 了员工的私人生活，但毫无疑问，在移民们被用恶劣的方式剥削的时代，亨利?福特却帮助 了许多人在美国扎下根来。>24 PianoThe ancestry of the piano can be traced to the early keyboard instruments of the fifteenth and sixteenth centuries    -- the spinet, the dulcimer, and the virginal. In the seventeenth century the organ, the clavichord, and the    harpsichord became the chief instruments of the keyboard group, a supremacy they maintained until the piano    supplanted them at the end of the eighteenth century. The clavichord's tone was metallic and never powerful;    nevertheless, because of the variety of tone possible to it, many composers found the clavichord a sympathetic    instrument for intimate chamber   music. The harpsichord with its bright, vigorous tone was the favorite instrument    for supporting the bass of the small orchestra of the period and for concert use, but the character of the tone    could not be varied save by mechanical or structural devices.The piano was perfected in the early eighteenth century by a harpsichord maker in Italy(though   musicologists point    out several   previous   instances of   the instrument). This instrument was called a piano e forte (soft and loud), to    indicate its dynamic versatility; its strings were struck by a recoiling hammer with a felt-padded head. The wires   were much heavier in the earlier instruments. A series of mechanical improvements continuing well into the nineteenth century, including the introduction of pedals to sustain tone or to soften it, the perfection of a metal frame, and steel wire of the finest quality, finally produced an instrument capable of myriad tonal effects from     the most delicate harmonies to an almost orchestral fullnessof sound, from a liquid, singing tone to a sharp,    percussive brilliance.钢琴钢琴的家系可以追溯至 15 至 16 世纪早期的键盘乐器，包括小型拨弦琴、洋琴和维金娜 琴。 17 世纪时风琴、敲弦琴和拨弦琴成为键盘乐器类的主要成员。 这种至高无上的地位 一直为它们所保持，直到 18 世纪末期钢琴将它们取代。 敲弦古钢琴的音调有金属的音质， 缺乏雄劲。 然而由于它的音调变化多，许多作曲家发现对于亲切的室内乐是一种得体的乐 器。 人们最喜欢用具备明快有力音调的拨弦古钢琴来配合当时小型管弦乐团的低音乐器以 及在演奏会上演奏。 但它的音调难以变化，除非使用机械或构件装置。18 世纪早期的意大 利，钢琴在一位拨琴钢琴制造者手中得到完善(尽管音乐理论家们指出有更早的例子)。 这 种乐器被称为 piano eforte (意大利语，柔和而响亮的)，以显示它有力的多样性。 演奏者用 一个头部带皮毡的弹击乐锤敲击琴弦。 更早的这种乐器之上的金属丝要重得多。 从此，持 续到 19 世纪的一系列机械上的改进，包括引入踏板以维持音调或使其柔和，改善金属框架， 以及使用最佳性能的钢丝，最终产生了一种具备无数音调效果的乐器。 这些效果涵盖了从 最精致的和声到几乎全部的管弦乐音响，从明快流畅的吟唱的音调到尖锐的打击乐器的清晰 动人的恢宏气势。>25 Movie MusicAccustomed though we are to speaking of the films made before 1927 as "silent", the film has never been, in the    full sense of the word, silent. From the very beginning, music was regarded as an indispensable accompaniment; when the Lumiere films were shown at the first public film exhibition in the United States in February 1896, they were    accompanied by piano improvisations on popular tunes. At first, the music played bore no special relationship to    the films; an accompaniment of any kind was sufficient. Within a very short time, however, the incongruity of    playing lively music to a solemn film became apparent, and film pianists began to take some care in matching their    pieces to the mood of the film.As movie theaters grew in number and importance, a violinist, and perhaps a cellist, would be added to the pianist    in certain cases, and in the larger movie theaters small orchestras were formed. For a number of years the    selection of music for each film program rested entirely in the hands of the conductor or leader of the orchestra,    and very often the principal qualification for holding such a position was not skill or taste so much as the    ownership of a large personal library of musical pieces. Since the conductor seldom saw the films until the night    before they were to be shown (if indeed, the conductor was lucky enough to see them then), the musical arrangement    was normally improvised in the greatest hurry.To help meet this difficulty, film distributing companies started the practice of publishing suggestions for    musical accompaniments. In 1909, for example, the Edison Company began issuing with their films such indications of mood as "pleasant", "sad", "lively". The suggestions became more explicit, and so emerged the musical cue    sheet containing indications of mood, the titles of suitable pieces of music, and precise directions to show where    one piece led into the next.Certain films had music especially composed for them. The most famous of these early special scores was that    composed and arranged for D. W. Griffith's film Birth of a Nation, which was released in 1915.电影插曲尽管我们习惯于将 1927 年以前的电影称为"无声电影"，但是就无声这个词完整的意义 上来说，电影从未真正的无声过，从最初开始音乐就被视为必不可少的伴奏。 当卢米埃尔 的电影在 1896 年 2 月美国首届影片公映展览上放映的时候，影片便用当时的流行曲临场钢 琴伴奏。 最初，这些音乐伴奏与电影没有什么特别的关系，用什么曲子伴奏都行。 但在很 短的时间内，为一部庄重的影片演奏快活的音乐所产生的不协调感变得显而易见，因此钢琴 家们开始注意将自己的作品与影片的情调结合起来。 随着影剧院在数量上与重要性上的不 断增长，在一些场合，除了钢琴师外，还要加上小提琴师，或许还有一位大提琴师。 较大 的影剧院里还组成了小型的管弦乐队。 在很长的时间内，为各部影片选择配乐完全掌握在 乐队指挥或队长手中，而通常把持这种职位的资格不是技巧或鉴赏品味，而是拥有一个大的 音乐作品的个人收藏。 因为直到电影上映的前一天晚上乐队指挥才能看到影片(如果这个指 挥真正有幸能够看到影片的话)，音乐安排通常是在非常匆忙的情况下临场进行的。为了解 决以上的困难，电影发行公司开办了为音乐伴奏印制提示单的业务。 例如 1909 年爱迪生公 司开始将一些诸如"喜悦的"、"悲伤的"、"活泼的"之类表明影片情调特征的提示与影片一起 发行。 这些提示逐渐变得更加具体，并且出现了包括影片情调说明、适用乐曲名称和乐曲 转换点等内容的配乐说明单。 某些影片拥有专门为其创作的音乐。 这些早期特创乐谱中最 著名的便是为 D. W. 格雷夫斯 1915 年上映的影片《一个国家的诞生》所创作的音乐。>26   International   Business   and Cross-cultural CommunicationThe increase in international business and in foreign investment has created a need for executives with knowledge    of foreign languages and skills in cross-cultural communication. Americans, however, have not been well trained in    either area and, consequently, have not enjoyed the same level of success in negotiation in an international arena    as have their foreign counterparts.Negotiating is the process of communicating back and forth for the purpose of reaching an agreement. It involves    persuasion and compromise, but in order to participate in either one, the negotiators must understand the ways in    which people are persuaded and how compromise is reached within the culture of the negotiation.In many international business negotiations abroad, Americans are perceived as wealthy and impersonal. It often   appears to the foreign negotiator that the American represents a large multi-million-dollar corporation that can    afford to pay the price without bargaining further. The American negotiator's role becomes that of an impersonal    purveyor of information and cash.In studies of American negotiators abroad, several traits have been identified that may serve to confirm this    stereotypical perception, while undermining the negotiator's position. Two traits in particular that cause    cross-cultural misunderstanding are directness and impatience on the part of the   American   negotiator. Furthermore,    American   negotiators often   insist on realizing short-term goals. Foreign negotiators, on the other hand, may value    the relationship established between negotiators and may be willing to invest time in it for long-term benefits. In order to solidify the relationship, they may opt for indirect interactions without regard for the timeinvolved in    getting to know the other negotiator.Clearly, perceptions and differences in values affect the outcomes of negotiations and the success of negotiators.    For Americans to play a more effective role in international business negotiations, they must put forth more effort to improve cross-cultural understanding.国际商业和跨文化交流 国际贸易和海外投资的增加产生了对具有外语知识和跨文化交 流技巧的经理的需求。 然而，美国人在这两方面未得到良好的训练，因此没有在国际谈判 中象他们的外国对手一样成功。 谈判是为了达成协议而反复交流的过程。 它包括说服和妥 协。 但是为了去进行说服和妥协，谈判者必须懂得在谈判的文化中怎样说服人和怎样达成 妥协。 在国外的国际商务谈判中，美国人被视为富有和不带个人情感。 在外国谈判者看来， 似乎美国人代表着一个庞大的拥有数百万资财的大企业，不用进一步地讨价还价就能出得起 价钱。 美国谈判者的角色变成了一个没有个人感情的信息及现金的供应者。 对在国外的美 国谈判者的研究中，我们找出了损害谈判者能力的几个特点，或许证实这个已成定式的看法。 尤其引起跨文化误解的两个特点是美国谈判者的直截了当和缺乏耐心。 此外，美国谈判者 经常坚持实现短期目标，而外国的谈判者会珍视建立谈判者之间的联系并愿意为长期利益投 入时间。 为了巩固这种联系，他们会选择非直接的交流而不计较投入用于了解对方的时间。 明显地，价值观的不同和理解上的差异影响了谈判的结果和谈判者的成功与否。 美国人要 在国际商务谈判中扮演更为有效的角色，他们就必须投入更多的努力提高跨文化的理解力。>27 Scientific TheoriesIn science, a theory is a reasonable explanation of observed events that are related. A theory often involves an    imaginary model that helps scientists picture the way an observed event could be produced. A good example of this    is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion.A useful theory, in addition to explaining past observations, helps to predict events that have not as yet been    observed. After a theory has been publicized, scientists design experiments to test the theory. If observations    confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the    scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or    rejected.Science involves imagination and creative thinking as well as collecting information and performing experiments.   Facts by themselves are not science. As the mathematician Jules Henri Poincare said,"Science is built with facts    just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of    bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires    considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called    hypotheses.In a way, any hypothesis is a leap into the unknown. It extends the scientist's thinking beyond the known facts.    The scientist plans experiments, performs calculations, and makes observations to test hypotheses. Without    hypothesis, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories.科学理论 在科学中，理论是对所观察到的相关事件的合理解释。 理论通常包含一个虚构的模型，这个模型帮助科学家构想所观察到的事件是如何发生的。 分子运动理论便是我们能找到的 一个很好的例子。 在这个理论中，气体被描绘成由许多不断运动的小颗粒组成。 一个有用 的理论，除了能够解释过去的观测，还有助于预测那些未被观测到的事件。 一个理论公开 后，科学家们设计实验来检验这个理论。 如果观察证实了科学家的预言，这个理论则得到 了验证。 如果观察不能证实科学家的预言，科学家就必须进一步的研究。 或许是实验存在 错误，或许是这个理论必须被修改或抛弃。 科学家除了收集信息和操作实验外还需要想象 能力和创/造性思维。 事实本身并不是科学。 正如数学家乔斯?亨利?波恩克尔所说："科 学建立在事实之上，就像房子用砖砌成一样。 但事实的收集不能被称作科学，就像一堆砖 不能被叫作房子一样。 "多数科学家通过找出别的科学家在一个特定问题上的所知来开始研 究。在收集了已知事实之后，科学家开始了研究中需要相当想像力的部分。 他们尔后拟订 对这个问题的可行的解决方法。这些可行的解决方式被称为假设。 在某种意义上，任何假 设都是向未知的跳跃。它使科学家的思维超越已知事实。科学家计划实验、计算、观测以检 验假定。若没有假设，进一步的研究便缺乏目的和方向。 当假设被证实了，就成为理论的 一部分。>28   Changing   Roles   of   Public EducationOne of the most important social developments that helped to make possible a shift in thinking about the role of    public education was the effect of the baby boom of the 1950's and1960's on the schools. In the 1920's, but    especially in the Depression conditions of the 1930's, the United States experienced a declining birth rate --    every thousand women aged fifteen to forty-four gave birth to about 118 live children in 1920，89.2 in 1930，75.8    in 1936, and 80 in1940. With the growing prosperity brought on by the Second World War and the economic boom that    followed it young people married and established households earlier and began to raise larger families than had    their predecessors during the Depression. Birth rates rose to 102 per thousand in 1946, 106.2 in 1950, and 118 in    1955. Although economics was probably the most important determinant, it is not the only explanation for the baby    boom. The increased value placed on the idea of the family also helps to explain this rise in birth rates. The baby boomers began streaming into the first grade by the mid 1940's and became a flood by 1950. The public school system suddenly found itself overtaxed. While the number of schoolchildren rose because of wartime and postwar conditions, these same conditions made the schools even less prepared to cope with the flood. The wartime economy meant that    few new schools were built between 1940 and 1945. Moreover, during the war and in the boom times that followed,    large numbers of teachers left their profession for better-paying jobs elsewhere in the economy.Therefore in the 1950's and 1960's, the baby boom hit an antiquated and inadequate school system. Consequently, the "custodial rhetoric"of the 1930's and early 1940's no longer made sense that is, keeping youths aged sixteen and    older out of the labor market by keeping them in school could no longer be a high priority for an institution    unable to find space and staff to teach younger children aged five to sixteen. With the baby boom, the focus of    educators and of laymen interested in education inevitably turned toward the lower grades and back to basic    academicskills and discipline. The system no longer had much interest in offering nontraditional, new, and extra   services to older youths.公共教育的角色变化 一项重要的、有可能促使人们对公共教育的角色的看法发生转变的社会发展是本世纪五六十年代的生育高峰对学校的影响。 在 20 年代，尤其是在 30 年代后的大萧条中，美国经 历了一次出生率的下降--1920 年每千名年龄在 15 岁至 45 岁的妇女生下大约 118 个存活婴儿，1930 年 89.2 个，1936 年 75.8 个，1940 年 80 个。 随着二战带来的持续繁荣以及随之而来 的经济增长，年轻人比大萧条中的同龄人更早地结婚成家，而且比前辈养育更大的家庭。1946 年出生率上升到 102%，1950 年达 106%，1955 年达 118%。 对于生育高峰，经济有可 能是最重要的决定因素，但它并不是唯一的解释。 不断受到重视的家庭观念也有助于解释 出生率的上升。 到 40 年代中期为止，这些生育高峰出生的孩子们开始源源不断地进入小学 一年级。 到了 1950 年，就形成了一股洪流。 公共教育系统突然感到不堪重负了。 由于战 时和战后的状况，使得学龄儿童人数增加，这些状况使得学校面对这股洪流更加措手不及。 战时经济意味着在 1940 年到 1950 年间几乎没有建立新学校。 而且，在战时和随后的经济 增长时期，大量的教师离开岗位去别处从事报酬更为优厚的工作。 因此，在五六十年代， 生育高峰冲击着陈旧而不完备的学校体系。 这样一来，30 年代以及 40 年代早期，"监护理 论"就不再有意义了。 也就是说，通过使 16 岁以上的年轻人留在学校不进入劳动力市场的 做法再也不是教育机构的优先考虑了。 因为教育机构不再能找到场地和教师来教育那些更 小的 5-16 岁的孩子。 随着生育高峰，教育者和圈外人士对教育的兴趣和焦点，不可避免地 转向了更低的年级和基础的学术技能和学科上。 这个系统不再有浓厚的兴趣给较年长的年 轻人提供非传统的新式的和额外的服务。>29 TelecommutingTelecommuting -- substituting the computer for the trip to the job -- has been hailed as a solution to all kinds of problems related to office work.For workers it promises freedom from the office, less time wasted in traffic, and help with child-care conflicts.    For management, telecommuting helps keep high performers on board, minimizes tardiness and absenteeism by    eliminating commutes, allows periods of solitude for high-concentration tasks, and provides scheduling flexibility.In some areas, such as Southern California and Seattle, Washington, local governments are encouraging companies to    start telecommuting programs in order to reduce rush-hour congestion and improve air quality.But these benefits do not come easily. Making a telecommuting program work requires careful planning and an    understanding of the differences between telecommuting realities and popular images.Many workers are seduced by rosy illusions of life as a telecommuter. A computer programmer from New York City    moves to the tranquil Adirondack Mountains and stays in contact with her office via computer. A manager comes in to his office three days a week and works at home the other two. An accountant stays home to care for her sick child;    she hooks up her telephone modem connections and does office work between calls to the doctor.These are powerful images, but they are a limited reflection of reality. Telecommuting workers soon learn that it    is almost impossible to concentrate on work and care for a young childat the same time. Before a certain age,    young children cannot recognize, much less respect, the necessary boundaries between work and family. Additional    child support is necessary if the parent is to get any work done.Management too must separate the myth from the reality. Although the media has paid a great deal of attention to   telecommuting in most cases it is the employee's situation, not the availability of technology that precipitates a    telecommuting arrangement.That is partly why, despite the widespread press coverage, the number of companies with work-at-home programs or    policy guidelines remains small.电子交通电子交通--用电脑取代上班的往返--作为对各种各样的办公室工作问题的解决办法已受 到了欢迎。 对工作者来说，它承诺不受办公室的约束，更少的时间浪费在交通上和有助于 解决照看小孩的矛盾。 对管理者来说，电子交通有助于挽留高效率的工作者，通过省去办 公室与家之间的来回往返，大大减少工作拖拉和旷工，给予管理者独处的时间来完成需要高 度集中精神的任务，为管理者提供灵活的时间安排。 在一些地区，如南加利福尼亚和西雅 图、华盛顿，地方政府鼓励公司开始电子交通计划以减少交通高峰时的塞车和提高空气质量。 但这些益处也来之不易。 要使电子交通成功需要仔细的计划并且理解电子交通的现实状况 和流行的想象之间的区别。 许多工作者被电子交通的美好幻想所迷惑。 一位电脑程序设计 员从纽约市搬到了宁静的阿第伦达克山，用电脑保持与她办公室之间的联系。 一位经理一 周三天到办公室，其他两天在家工作；一位会计师在家照顾她生病的孩子，接通电话调制解 调器的接头，在同医生通话之余完成办公室工作。 这些是很有震撼力的情景，但也是对现 实有限的反映。 电子交通者很快发现在同一时间专注工作和照看小孩几乎是不可能的。 在 某个年龄之前，小孩子不可能意识到，更不可能尊重工作与家庭之间的界限。 如果家长要 完成工作，就必须另外照看小孩。 管理阶层必须把现实同神话分开。 虽然传媒对电子交通 投入了极大的关注，但在很大程度上，是员工的实际情况而不是技术的可能性促成电子交通 的安排。 这就是为什么尽管有广泛的报导，具有在家工作项目或行动纲领的公司数目依然 很少的部分原因。 >30 The Origin of RefrigeratorsBy the mid-nineteenth century, the term"icebox"had entered the American language, but ice was still only    beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of    cities. Ice was used in hotels, taverns, and hospitals, and by some forward-looking   city dealers in fresh   meat,   fresh fish, and   butter.   After the Civil   War(1861-1865), as ice was used to refrigerate freight cars, it also came    into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of    that sold in Boston and Chicago, went to families for their own use. This had become possible because a new    household convenience, the icebox, a precursor of the modern refrigerator, had been invented.Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge    of the physics of heat, which was essential to a science of refrigeration, was rudimentary. The commonsense notion    that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of    the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in    blankets, which keptthe ice from doing its job. Not until near the end of the nineteenth century did inventors    achieve the delicate balance of insulation and circulation needed for an efficient icebox.But as early as 1803, an ingenious Maryland farmer, Thomas Moore, had been on the right track. He owned a farm    about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When    he used an icebox of his own design to transport his butter to market, he found that customers would pass up the    rapidly melting stuff in the tubs of his competitors to pay a premium price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, more explained, was that farmers would no longer have to    travel to market at night in order to keep their produce cool.冰箱的由来直到 19 世纪中期，"冰箱"这个名词才进入了美国语言，但冰仅仅只是开始影响美国普 通市民的饮食。 冰的买卖随着城市的发展而发展。 冰被用在旅馆、酒馆、医院以及被一些 有眼光的城市商人用于肉、鱼和黄油的保鲜。 内战(1861-1865)之后，冰被用于冷藏货车， 同时也进入了民用。 甚至在 1880 年前，半数在纽约、费城和巴尔的摩销售的冰，三分之一 在波士顿和芝加哥销售的冰进入家庭使用，因为一种新的家庭设备，冰箱，即现代冰箱的前 身，被发明了。 制造一台有效率的冰箱不像我们想象的那么简单。 19 世纪早期，关于对 冷藏科学至关重要的热物理知识是很浅陋的。 认为最好的冰箱应该防止冰的融化这样一个 普遍的观点显然是错误的，因为正是冰的融化起了制冷作用。 早期为节省冰的努力，包括 用毯子把冰包起来，使得冰不能发挥它的作用。 直到近 19 世纪末，发明家们才成功地找到 有效率的冰箱所需要的精确的隔热和循环的精确平衡。 但早在 1803 年，一位有发明天才的 马里兰农场主，托马斯?莫尔，找到了正确方法。 他拥有一个农场，离华盛顿约 20 英里， 那里的乔治镇村庄是集市中心。 当他用自己设计的冰箱运送黄油去市场时，他发现顾客们 会走过装在竞争者桶里那些迅速融化的黄油而给他比市价更高的价格买他仍然新鲜坚硬，整 齐地切成一磅一块的黄油。 莫尔说他的冰箱的一个好处是使得农民们不必在夜里上路去市 场以保持他们产品的低温。>31 British ColumbiaBritish Columbia is the third largest Canadian province, both in area and population. It is nearly 1.5 times as    large as Texas, and extends 800 miles (1,280km) north from the United States border. It includes Canada's entire    west coast and the islands just off the coast.Most of British Columbia is mountainous, with long rugged ranges running north and south. Even the coastal islands    are the remains of a mountain range that existed thousands of years ago. During the last Ice Age, this range was    scoured by glaciers until most of it was beneath the sea. Its peaks now show as islands scattered along the coast.The southwestern coastal region has a humid mild marine climate. Sea winds that blow inland from the west are    warmed by a current of warm water that flows through the Pacific Ocean. As a result, winter temperatures average    above freezing and summers are mild. These warm western winds also carry moisture from the ocean.Inland from the coast, the winds from the Pacific meet the mountain barriers of the coastal ranges and the Rocky    Mountains. As they rise to cross the mountains, the winds are cooled, and their moisture begins to fall as rain. On some of the western slopes almost 200 inches (500cm) of rain fall each year.More than half of British Columbia is heavily forested. On mountain slopes that receive plentiful rainfall, huge    Douglas firs rise in towering columns. These forest giants often grow to be as much as 300 feet (90m) tall, with    diameters up to 10 feet (3m). More lumber is produced from these trees than from any other kind of tree in North    America. Hemlock, red cedar, and balsam fir are among the other trees found in British Columbia.英属哥伦比亚英属哥伦比亚是加拿大的第三大省，无论是面积还是人口都是如此。 它几乎是德克萨 斯的 1.5 倍，从美国边境一直向北延伸了 800 英里(1，280 公里)。 它包括了加拿大整个西 海岸及附近岛屿。 大部分英属哥伦比亚多山峦。 绵长而粗犷的山脉贯通南北。 甚至那些 沿海的岛屿都是那些存在于千万年前的山脉的遗迹。 在上一个冰河时期，这些山脉被冰河 冲刷侵蚀，直到大部分山脉被淹没在海中。 它们的峰顶显现为沿着海岸散布的岛屿。 西南 海岸地区有着潮湿温和的海洋性气候。 从太平洋来的温暖的洋流使得从西吹过内陆的海风 变得温暖。 因此这儿冬天平均气温在零上而且夏天也不会酷热。 这些温暖的西风同样也从 海洋带来了湿气。 来自太平洋的、从海岸向内陆的风遇到海岸山脉和落基山脉这些山脉屏 障。 当气流升高跨越这些山脉时，风的温度就降低了，风中的水分形成降雨。 在一些朝西 山坡区域每年大约有 200 英寸(500 厘米)的降水。 大部分英属哥伦比亚密布着森林。 在有 充足降水的斜坡，巨大的道格拉斯枞树高耸入云。 这些森林巨人常常长到高达 300 英尺(90 米)，直径粗达 10 英尺(3 米)。 这些树产出了比北美其他任何树都多的木材。 铁杉、红香 椿、香脂冷杉枞都是发现于英属哥伦比亚的其它树种。>32 BotanyBotany, the study of plants, occupies a peculiar position in the history of human knowledge. For many thousands of   years it was the one field of awareness about which humans had anything more than the vaguest of insights. It is    impossible to know today just what our Stone Age ancestors knew about plants, but from what we can observe of    preindustrial societies that still exist a detailed learning of plants and their properties must be extremely    ancient. This is logical. Plants are the basis of the food pyramid for all living things even for other plants.    They have always been enormously important to the welfare of people not only for food, but also for clothing,    weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes living today in the jungles of    the Amazon recognize literally hundreds of plants and know many properties of each. To them, botany, as such, has        no name and is probably not even recognized as a special branch of "knowledge"at all.Unfortunately, the more industrialized we become the farther away we move from direct contact with plants, and the    less distinct our knowledge of botany grows. Yet everyone comes unconsciously on an amazing amount of botanical    knowledge, and few people will fail to recognize a rose, an apple, or an orchid. When our Neolithic ancestors,    living in the Middle East about 10, 000 years ago, discovered that certain grasses could be harvested and their    seeds planted for richer yields the next season the first great step in a new association of plants and humans was    taken. Grains were discovered and from them flowed the marvel of agriculture: cultivated crops. From then on,    humans would increasingly take their living from the controlled production of a few plants, rather than getting a    little here and a little there from many varieties that grew wild - and the accumulated knowledge of tens of    thousands of years of experience andintimacy with plants in the wild would begin to fade away.植物学植物学，即对植物的研究，在人类知识的历史中占据了特殊的地位。 这是人类几千年 来超越模糊的认知而真正有所了解的领域之一。 我们今天不可能知道新石器时代的祖先们 对植物到底了解多少，但我们在至今仍存在的前工业化社会观察到：人类对植物及其特性的 详细了解应该是非常古老的。 这是理所当然的。 植物是其他生物甚至其他植物食物金字塔 的基础。 它们对人们的生活至关重要，不仅在食物上，而且在衣物、武器、工具、染料、 药物、住所和许许多多其他的用途上。 至今仍生活在亚马逊河丛林中的部落确实能够辨识 几百种植物并知道每一种的许多特性。 对他们来说，植物学没有专门的名称，甚至可能根 本未被认为是一种专门知识。 不幸的是，工业化的程度越高，我们距直接与植物接触就越 远，我们的植物学知识的增加也就越微不足道。 然而每个人在不知不觉中拥有大量的植物 学知识，很少有人认不出玫瑰、苹果或兰花。 大约一万年前居住在中东的新时代的祖先们 发现某些草能被收获，它们的种子下一季耕种会收获更多时，人类就迈出了人和植物之间的 新关系第一大步。 谷子被发现后，农业的奇迹从此诞生：这就是可栽培的谷物。 从那时起， 人类越来越依赖少数可控制的作物生存，而不再是从众多的野生种类中这里获取一点，那里 获取一点。 这样在千万年中对于野生植物的经验和密切联系中积累起来的知识就开始消失 了。 >33 PlanktonScattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of    these plants and animals are too small for the human eye to see. They drift about lazily with the currents,    providing a basic food for many larger animals.Plankton has been described as the equivalent of the grasses that grow on the dry land continents, and the    comparison is an appropriate one. In potential food value, however, plankton far outweighs that of the land    grasses. One scientist has estimated that while grasses of the world produce about 49 billion tons of valuable    carbohydrates each year, the sea's plankton generates more than twice as much.Despite its enormous food potential, little effect was made until recently to farm plankton as we farm grasses on    land. Now marine scientists have at last begun to study this possibility, especially as the sea's resources loom   even more important as a means of feeding an expanding world population.No one yet has seriously suggested that "planktonburgers" may soon become popular around the world. As a possible farmed supplementary food source, however, plankton is gaining considerable interest among marine scientists.One type of plankton that seems to have great harvest possibilities is a tiny shrimplike creature called krill.    Growing to two or three inches long, krill provide the major food for the great blue whale, the largest animal ever inhabit the Earth. Realizing that this whale may grow to100 feet and weigh 150 tons at maturity, it is not    surprising that each one devours more than one ton of krill daily.浮游生物 数十亿吨的被称为"浮游生物"的小动物、植物散布在世界的海洋中。 这些小 的动、植物大多太小而难以被人眼看到。 它们随波逐流，为许多较大的动物提供了基本的 食物。 浮游生物曾被描述为生长在大陆陆地上的各种草类的海洋对应物。 这种比喻是恰当的。 然而就潜在的食物价值而言，浮游生物远胜于草类。 一位科学家曾经估计，世界上的 草类每年生产大约 490 亿吨有用的碳水化合物，而海洋里的浮游生物每年生产的碳水化合物 多于此数的两倍。 尽管浮游生物具备巨大的食物潜能，但直到最近人们还很少象种植草类 那样付出努力养殖浮游生物。 现在，海洋科学家们至少已开始研究这种可能性。 全球人口 不断扩张，海洋资源作为食品的重要性日益突出。 现在还没有人认真说过"浮游生物汉堡" 会很快在世界上流行起来。 然而，作为一种可能养殖的补充性食物资源，浮游生物正引起 了海洋科学家们相当大的兴趣。 一种似乎具有很大收获可能性的微小的虾状浮游生物被称 为鳞虾。 鳞虾长至 2～3 英寸长时即成为地球上曾居住过的最大动物--蓝鲸的主要食物。 成 熟的蓝鲸可以达到 100 英尺长，150 吨重，所以每头鲸每天吞食 1 吨多的鳞虾一点也不让人 吃惊。>34 Raising OystersIn the past oysters were raised in much the same way as dirt farmers raised tomatoes - by transplanting them.   First, farmers selected the oyster bed, cleared the bottom of old shells and other debris, then scattered clean    shells about. Next, they "planted" fertilized oyster eggs, which within two or three weeks hatched into larvae.    The larvae drifted until they attached themselves to the clean shells on the bottom. There they remained and in    time grew into baby oysters called seed or spat. The spat grew larger by drawing in seawater from which they    derived microscopic particles of food. Before long, farmers gathered the baby oysters, transplanted them in other waters to speed up their growth, then transplanted them once more into another body of water to fatten them up.Until recently the supply of wild oysters and those crudely farmed were more than enough to satisfy people's needs.But today the delectable seafood is no longer available in abundance. The problem has become so serious that some    oyster beds have vanished entirely.Fortunately, as far back as the early 1900's marine biologists realized that if new measures were not taken,    oysters would become extinct or at best a luxury food. So they set up well-equipped hatcheries and went to work.    But they did not have the proper equipment or the skill to handle the eggs. They did not know when, what, and how    to feed the larvae. And they knew little about the predators that attack and eat baby oysters by the millions. They failed, but they doggedly kept at it. Finally, in the 1940's a significant breakthrough was made.The marine biologists discovered that by raising the temperature of the water, they could induce oysters to spawn    not only in the summer but also in the fall, winter, and spring. Later they developed a technique for feeding the    larvae and rearing them to spat. Going still further, they succeeded in breeding new strains that were resistant to diseases, grew faster and larger, and flourished in water of different salinities and temperatures. In addition,    the cultivated oysters tasted better!饲养牡蛎过去人们饲养牡蛎的方式很大程度上类似于田地里的农夫种植蕃茄--通过移植来饲养 它们。 首先，农夫选好牡蛎苗床，清除底部的旧壳和其它杂物，然后四处撒播干净的壳。 接 着，他们"栽种"已受精的牡蛎卵。 这些卵在 2～3 周内会孵化成幼贝。 幼贝一直漂流直到 粘在苗床底部干净的壳上为止。 它们会呆在那儿并逐渐长成小牡蛎。 我们称之为种子或贝苗。 贝苗吸进海水中的微小生物作为食物从而越长越大。 不久之后，农夫将这些小牡蛎收 集起来，把它们移种进其他的水域加快其生长，然后再次将它们移种进另外的水域以使其肥 壮起来。 直到最近，野生的以及人工饲养的牡蛎完全能够满足人们的需要。 但是今天这种 可口的海味已不再大量存在。这个问题已经变得如此严重以至于一些牡蛎苗床已完全消失。 幸运的是，早在 20 世纪初期海洋生物学家们就意识到如果不采取新的措施，牡蛎将会灭绝 或至少会变为一种奢侈的食品。 因此他们建造了装备良好的孵卵场所并开始工作。 但是他 们尚没有适当的装置或技术来处理牡蛎卵。他们不知道何时、用什么以及如何喂养幼贝。他 们对捕食数百万幼小牡蛎的动物天敌也所知无几。 他们失败了，但他们顽强地坚持了下来。 终于，在 20 世纪 40 年代，一个重要的突破性的进展产生了。 海洋生物学家发现，升高水 温能够诱导牡蛎不仅在夏季也在秋季、冬季和春季里产卵。 后来他们发展了一项技术来喂 养幼贝至其长成贝苗。 他们进一步成功地培养出了新的品种，可以抵抗疾病、长得更快、 更大并且在不同的盐度和温度的水中都能茁壮生长。 此外，这些培殖出的牡蛎口感更佳!>35 Oil RefiningAn important new industry, oil refining, grew after the Civil War. Crude oil, or petroleum -- a dark, thick ooze    from the earth -- had been known for hundreds of years, but little use had ever been made of it. In the 1850's    Samuel M. Kier, a manufacturer in western Pennsylvania, began collecting the oil from local seepages and refining    it into kerosene. Refining, like smelting, is a process of removing impurities from a raw material.Kerosene was used to light lamps. It was a cheap substitute for whale oil, which was becoming harder to get. Soon    there was a large demand for kerosene. People began to search for new supplies of petroleum.The first oil well was drilled by E. L. Drake, a retired railroad conductor. In 1859 he began drilling in    Titusville, Pennsylvania. The whole venture seemed so impractical and foolish that onlookers called it "Drake's    Folly". But when he had drilled down about 70 feet (21 meters), Drake struck oil. His well began to yield 20    barrels of crude oil a day.News of Drake's success brought oil prospectors to the scene. By the early 1860's these wildcatters were drilling    for "black gold" all over western Pennsylvania. The boom rivaled the California gold rush of 1848 in its    excitement and Wild West atmosphere. And it brought far more wealth to the prospectors than any gold rush.Crude oil could be refined into many products. For some years kerosene continued to be the principal one. It was    sold in grocery stores and door-to-door. In the 1880's refiners learned how to make other petroleum products such    as waxes and lubricating oils. Petroleum was not then used to make gasoline or heating oil.炼油一种重要的新兴工业--炼油业在国内战争后成长起来。 未加工的石油，或原油--一种深 色的地下的稠浆--数百年来一直为大众所知，但是人们却很少使用过它。 在十九世纪五十 年代，萨缪尔?M?科尔，宾西法尼亚西部的一位制造商，开始从当地的溢出物中收集石油 并将它炼成煤油。与冶炼矿石一样，石油提炼是一个从未加工的原料中除去杂质的过程。煤 油被用来点灯。 它是鲸油的一种便宜的替代品，而鲸油正变得越来越难以获得。 不久就产 生了对煤油的大量需求。 人们开始寻找新的石油供应。 第一口油井为 E?L?瑞克，一个 退休的火车检票员所钻得。 1859 年他开始在宾西法尼亚的泰特斯维尔钻井。 整个的这项冒险事业看起来是如此不现实和愚蠢以致旁观者称之为"鸭子的蠢行"。 (译者注：Drake's Folly, drake 在这里意含双关，即指瑞克的名字，又指该词的本义即鸭子。 )但当瑞克往下钻 至 70 英尺(21 米)的时候，他发现了石油。 他的油井从此每天生产 20 桶原油。 瑞克成功的 消息将石油勘探者们吸引到现场。 截止到 19 世纪 60 年代早期，这些冒险者为寻找"黑色的 金子"钻探遍了整个宾西法尼亚西部。 这项繁荣的事业在刺激性和粗犷的西部气氛上可与1848 年的加州淘金热相媲美，而且它为勘探者带来了远超过淘金潮的财富。 原油能被提炼 成许多产品。 多年以来煤油一直是主要的一种产品。 它在杂货店中出售由人挨户推销。 19 世纪八十九十年代炼油者们懂得了生产其它石油产品，如蜡和润滑油。 那时石油还没有被 用来制造汽油或采暖装置用油。>36   Plate   Tectonics   and   Sea-floor SpreadingThe theory of plate tectonics describes the motions of the lithosphere, the comparatively rigid outer layer of the    Earth that includes all the crust and part of the underlying mantle. The lithosphere is divided into a few dozen    plates of various sizes and shapes, in general the plates are in motion with respect to one another. A mid-ocean   ridge is a boundary between plates where new lithospheric material is injected from belows. As the plates diverge    from a mid-ocean ridge they slide on a more yielding layer at the base of the lithosphere.Since the size of the Earth is essentially constant, new lithosphere can be created at the mid-ocean ridges only if an equal amount of lithospheric material is consumed elsewhere. The site of this destruction is another kind of    plate boundary: a subduction zone. There one plate dives under the edge of another and is reincorporated into the    mantle. Both kinds of plate boundary are associated with fault systems, earthquakes and volcanism, but the kinds of geologic activity observed at the two boundaries are quite different.The idea of sea-floor spreading actually preceded the theory of plate tectonics. In its original version, in the        early 1960's, it described the creation and destruction of the ocean floor, but it did not specify rigid    lithospheric plates. The hypothesis was substantiated soon afterward by the discovery that periodic reversals of    the Earth's magnetic field are recorded in the oceanic crust. As magma rises under the mid-ocean ridge,   ferromagnetic minerals in the magma become magnetized in the direction of the geomagnetic field. When the magma    cools and solidifies, the direction and the polarity of the field are preserved in the magnetized volcanic rock.    Reversals of the field give rise to a series of magnetic stripes running parallel to the axis of the rift. The oceanic crust thus serves as a magnetic tape recording of the history of the geomagnetic field that can be dated    independently; the width of the stripes indicates the rate of the sea-floor spreading.板块结构与海床扩展板块结构理论描述岩石圈的运动。 岩石圈是相对坚硬的地球外层，包括全部地壳和部 分地幔。 岩石圈被划分为几十个大小不同形状各异的板块，一般而言这些板块都处于相对 运动之中。 一道中海脊是板块之间的边界，在那里新的岩石圈的物质从下部注入。 当板块 从中海脊脱离时，它们滑向在岩石圈基部较易变形的地层上。 因为地球的大小本质上是不 变的，只有同等数量的岩石圈物质在其它地方被吞没，新的岩石圈才能生成。 销毁旧岩石圈的地方形成另外一种板块边界：一块潜没的区域。 在这里，一块板块潜没到另一板块的 边缘之下并结合入地幔之中。 两种板块边界均与地层系统、地震以及火山活动有关，但在 两种边界处观察到的诸般地质活动却迥然不同。 海床扩展说实际上早于板块结构理论。 在20 世纪 60 年代它的理论雏形中，描述了海底的生成和毁灭，但没有详细介绍坚硬的岩石圈 板块。 这个假定不久之后为发现所证实。 该发现表明地球磁场周期性的逆转被记录在海洋 地壳中。 当岩浆从中海脊下涌起的时候，岩浆中的磁铁矿物质按地磁场的方向被磁化。 岩 浆冷却并凝固下来后，地磁场的方向和磁极被保留在磁化了的火山岩中。 磁场的逆转形成 一系列与断层轴线平行的条形磁区。 这样海洋壳就扮演了磁带的角色，记录下可以鉴定时 间的地磁场的历史。 条形磁区的宽度表明了海底扩展的速度。>37 IcebergsIcebergs are among nature's most spectacular creations, and yet most people have never seen one. A vague air of    mystery envelops them. They come into being -- somewhere -- in faraway, frigid waters, amid thunderous noise and    splashing turbulence, which in most case no one hears or sees. They exist only a short time and then slowly waste    away just as unnoticed.Objects of sheerest beauty they have been called. Appearing in an endless variety of shapes, they may be dazzlingly white, or they may be glassy blue, green or purple, tinted faintly or in darker hues. They are graceful, stately,    inspiring -- in calm, sunlight seas.But they are also called frightening and dangerous, and that they are -- in the night, in the fog, and in storms.    Even in clear weather one is wise to stay a safe distance away from them. Most of their bulk    is hidden below the    water, so their underwater parts may extend out far beyond the visible top.       Also, they may roll over unexpectedly, churning the waters around them.Icebergs are parts of glaciers that break off, drift into the water, float about awhile, and finally melt. Icebergs afloat today are made of snowflakes that have fallen over long ages of time. They embody snows that drifted down    hundreds, or many thousands, or in some cases maybe a million years ago. The snows fell in polar regions and on    cold mountains, where they melted only a little or not at all, and so collected to great depths over the years and    centuries.As each year's snow accumulation lay on the surface, evaporation and melting caused the snowflakes slowly to lose    their feathery points and become tiny grains of ice. When new snow fell on top of the old, it too turned to icy    grains. So blankets of snow and ice grains mounted layer upon layer and were of such great thickness that the    weight of the upper layers compressed the lower ones. With time and pressure from above, the many small ice grains    joined and changed to larger crystals, and eventually the deeper crystals merged into a solid mass of ice.冰山 冰山是大自然最壮观的创造之一，但大多数人却从未看到过冰山，一种朦胧神秘的气氛笼罩着它们。 冰山形成于久远的、寒冷的水体中，而且伴随着雷声轰鸣般的嘈杂和水花汹 涌的风暴，但却无人耳闻目睹。冰山仅存在短短的一段时间就慢慢地悄无声息地融化掉。冰 山具有最纯粹的美，人们如是说。 冰山呈现出千姿百态，可能白得耀眼，或者是闪耀着蓝 色、绿色或紫色的玻璃般的光芒，或浓或淡。 它们在平静的阳光照耀的海水中显得优雅堂 皇，令人浮想联翩。 但是人们亦把冰山称为恐怖的和危险的。 它们的确如此--在夜间，雾 天和风暴肆虐时。 即便是在晴朗的天气里，与它们保持一段安全距离也是明智的。 冰山的 大部分体积稳藏于水下，因此其水下部分的伸展远远超过可见的顶部。 冰山也可能出人意料地翻滚，剧烈地搅动周围的水体。 冰山是冰川的一部分，从冰川断裂漂流进水中，一段 时间后融化。 今天的冰山由多年前降落的雪花形成。 它们的体内是数百年，或数千年，有 时甚至是数百万年前的降雪。 这些雪花落在极地或寒冷的山上，仅有少量融化或根本不融 化，这样经过许多年或许多世纪后积累了巨大的深度。 由于每年的雪花积累在表面之上， 蒸发和融化使得雪花慢慢失去其羽状尖端而变成微小的冰粒。 当新的雪花降落到旧的表面 上，也变成了冰粒。 因而雪花覆盖层和冰粒层层堆积起来直到如此之大的厚度以致较上层 的重量压缩较下层。 在时间和压力的作用下，许多小冰粒结合到一起变成更大的晶体，最 终较底层的晶体合并成庞大而坚固的冰块。>38 TopazTopaz is a hard, transparent mineral. It is a compound of aluminum, silica, and fluorine. Gem topaz is valuable.    Jewelers call this variety of the stone "precious topaz". The best-known precious topaz gems range in color from rich yellow to light brown or pinkish red. Topaz is one of the hardest gem minerals. In the mineral table of    hardness, it has a rating of 8, which means that a knife cannot cut it, and that topaz will scratch quartz.The golden variety of precious topaz is quite uncommon. Most of the world's topaz is white or blue. The white and    blue crystals of topaz are large, often weighing thousands of carats.    For this reason, the value of topaz does not depend so much on its size as it does with diamonds and many other precious stones, where the value increases about four times with each doubling of weight. The value of a topaz is largely determined by its quality. But color is    also important: blue topaz, for instance, is often irradiated to deepen and improve its color.Blue topaz is often sold as aquamarine and a variety of brown quartz is widely sold as topaz. The quartz is much    less brilliant and more plentiful than true topaz. Most of it is a variety of amethyst: that heat has turned brown.黄水晶黄水晶是一种坚硬、透明的矿物质。 它是铝、硅和氟的化合物。 黄水晶宝石价值不菲。 珠宝商把这种石头称为"黄玉"。 最出名的黄玉有各种颜色如深黄色、淡棕色、浅红色等。 黄 水晶是最坚硬的宝石矿中的一种。 在矿石硬度表上，它的硬度为 8，这表明刀子不能割开 它而它可在石英上划痕。 金黄色的黄玉品种非常罕见。 世界上大多数的黄水晶是白色或蓝 色的。 这些白色或蓝色的黄水晶晶体很大，常常有数千克拉重。 由于这个原因，黄水晶的 价值不像钻石和许多其它宝石那样主要依赖于其大小，重量翻一番价值即上升约四倍。 黄 水晶的价值很大程度上取决于其品质，但颜色也很重要。 举例来说，蓝色的黄水晶常需放 射处理以加深和改善其颜色。 蓝色的黄水晶常被作为海蓝宝石出售，许多种棕色石英被当 作黄水晶广为贩卖。 石英光亮度远小于黄水晶，矿藏储量也远较黄水晶丰富。 大多数石英 是一种紫水晶，高温使其变为棕色。>39 The Salinity of Ocean WatersIf the salinity of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless,    some of these small changes are important. There are three basic processes thatcause a change in oceanic salinity.One of these is the subtraction of water from the ocean by means of evaporation - conversion of liquid water to    water vapor. In this manner the salinity is increased, since the salts stay behind. If this is carried to the    extreme, of course, white crystals of salt would be left behind.The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions   where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or    decreased by the addition of fresh water by precipitation or runoff.Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in    other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute    the sea, salinity is somewhat lower than in other oceanic areas.A third process by which salinity may be altered is associated with the formation and melting of sea ice. When sea    water is frozen, the dissolved materials are left behind. In this manner, sea water directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to    decrease the salinity of the surrounding water.    In the Weddell Sea Antarctica, the densest water in the oceans is formed as a result of this freezing process,    which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the    oceans of the world.海水盐度 如果我们分析海水的盐度，会发现地区间只有轻微的变化，然而有些小的变化是重要的。导致海洋的盐度变化的基本过程有三个，其中之一是通过蒸发的方式即把液态水转化为水蒸 气来减少海洋中的水分。 这样由于盐留了下来，所以盐度增大。 当然，如果这种方式走向 极端，将会余下白色的盐晶体。 与蒸发相反的是降水，如降雨，由此水被加入海中，海水 被稀释，从而盐度降低。 这种情形会发生在大量降雨的地区，或江河入海岸处。 因此，盐 度通过蒸发减少水分而上升或通过降水或径流增加淡水成分而下降。 一般来说，在阳光很 强烈的热带地区，海水的盐度略高于世界上其它没有热带那样多的蒸发的地区。 同理，在 江河稀释海水的海岸地带，海水盐度略低于其它海区。 第三个可以变更盐度的过程与海洋 中冰的形成和融化有关。 海水冻结时，溶于其中的物质被留了下来。 这样，在新形成的海 水冰面的正下方的海水比在冰形成之前有更高的盐度。 当然，当冰融化的时候，会降低周 围水中的盐度。 在南极洲边缘的威德尔海中，结冰过程增加低温海水的盐度，从而形成了 浓度最大的海水。 这些大密度的海水下沉，可以在世界海洋的深水域发现。  >40 Cohesion-tension TheoryAtmospheric pressure can support a column of water up to 10 meters high. But plants can move water much higher; the sequoia tree can pump water to its very top more than 100 meters above the ground. Until the end of the nineteenth    century, the movement of water in trees and other tall plants was a mystery. Some botanists hypothesized that the    living cells of plants acted as pumps. But many experiments demonstrated that the stems of plants in which all the    cells are killed can still move water to appreciable heights. Other explanations for the movement of water in    plants have been based on root pressure, a push on the water from the roots at the bottom ofthe plant. But root    pressure is not nearly great enough to push water to the tops of tall trees. Furthermore, the conifers, which are    among the tallest trees, have unusually low root pressures.If water is not pumped to the top of a tall tree, and if it is not pushed to the top of a tall tree, then we may    ask: how does it get there? According to the currently accepted cohesion-tension theory, water is pulled there. The pull on a rising column of water in a plant results from the evaporation of water at the top of the plant. As water is lost from the surface of the leaves, a negative pressure, or tension, is created. The evaporated water is    replaced by water moving from inside the plant in unbroken columns that extend from the top of a plant to its    roots. The same forces that create surface tension in any sample of water are responsible for the maintenance of these unbroken columns of water. When water is confined in tubes of very small bore, the forces of cohesion (the    attraction between water molecules) are so great that the strength of a column of water compares with the strength    of a steel wire of the same diameter. This cohesive strength permits columns of water to be pulled to great heights without being broken.内聚压力理论大气压能够支持 10 米高的水柱，但植物可将水送得更高。 美洲红杉就能把水泵到地面 以上 100 多米高的树顶。 直到 19 世纪末，水在树木和其它高大植物中的输送还是一个谜。 一些植物学家假定植物中的活细胞充当了水泵的角色。 但许多实验表明细胞都已死亡的植 物茎干仍能将水输送到相当可观的高度。 对于植物中输送水的其它解释都基于根压--植物 底端的根对水的推动。 但根压完全不足以将水推到树顶。 况且，最高树木中的松柏只有很 低的根压。 如果水不是被泵到高树的树顶，也不是被推到树顶，那么我们会问：它是怎样 到达树顶的呢?根据目前为人们所接受的内聚压力的理论，水是被拉到上面去的。 一株植物 中作用于一个正在升高的水柱之上的拉力来自该植物顶部水的蒸发。 由于水从叶子表面丧 失，一个负压力，或张力就得以产生。 蒸发出去的水被植物里流动的水代替。 这些水形成 水柱从植物顶端一直延伸到根部。在任何水样中造成表面张力的力支持着这些不断的水柱。 当水被限制在内径很小的管道中时，内聚压力(水分子之间的相互吸引力)是如此之大以致一 支水柱的强度相当于一根直径相同的钢丝的强度。 这种内聚压力使得水柱被拉到非常高的 地方而不会断裂。>41 American Black BearsAmerican black bears appear in a variety of colors despite their name. In the eastern part of their range, most of    these bears have shiny black fur, but in the west they grow brown, red, or even yellow coats. To the north, the    black bear is actually gray or white in color. Even in the same litter, both brown and black furred bears may be    born.Black bears are the smallest of all American bears, ranging in length from five to six feet, weighing from three    hundred to five hundred pounds. Their eyes and ears are small and their eyesight and hearing are not as good as    their sense of smell.Like all bears, the black bear is timid, clumsy, and rarely dangerous, but if attacked, most can climb trees and    cover ground at great speeds. When angry or frightened, it is a formidable enemy.Black bears feed on leaves, herbs, roots, fruit, berries, insects, fish, and even larger animals. One of the most    interesting characteristics of bears, including the black bear, is their winter sleep. Unlike squirrels, woodchucks, and many other woodland animals, bears do not actuallyhibernate. Although the bear does not eat during the winter months, sustaining itself from body fat, its temperature remains almost normal, and it breathes    regularly four or five times per minute.Most black bears live alone, except during mating season. They prefer to live in caves, hollow logs, or dense    thickets. A litter of one to four cubs is born in January or February after a gestation period of six to nine    months, and they remain with their mother until they are fully grown or about one and a half years old. Black bears can live as long as thirty years in the wild, and even longer in game preserves set aside for them.美国黑熊美国黑熊虽然被叫做黑熊但却有各种各样的颜色。 在它们生活区域的东部，大部分黑 熊长有富有光泽的黑毛，但在西部，他们则长着棕色、红色甚至是黄色的毛。 在北部，黑 熊其实长着灰色或白色的毛。 就是在一胎所生的小熊中，都可能混杂棕毛和黑毛。 黑熊是 所有美洲熊中最小的，5～6 英尺长，300～500 磅重。 它们的眼睛和耳朵都很小，他们的视 力和听觉不如嗅觉那样好。 像所有的熊一样，黑熊胆小，笨拙，很少具有危险性。 但如果 受到攻击，大部分黑熊会以很快的速度爬上树和奔跑。 当发怒或受惊吓时，黑熊会成为可 怕的对手。 黑熊以树叶、草、树根、水果、浆果、昆虫、鱼，甚至更大的动物为食。 熊类， 包括黑熊的最有趣的一个特点是他们的冬眠。 与松鼠、旱獭和其它别的林地动物不同，熊 并不真正地冬眠。 虽然熊在冬天的几个月中不吃东西，靠体内脂肪维持生命，但它们的体 温保持正常，并有规律地一分钟呼吸 4 或 5 次。除交配季节外，大多数黑熊独自生活。 他 们喜欢住在洞里、空心的大木头里或茂密的树丛里。 经过 6 到 9 个月的怀孕期后一胎 1～4 个小熊在 1 月或 2 月出生。 它们同母熊住在一起，直到它们完全长大，即 1 岁半左右。 黑 熊在野外可以活到长达 30 年，在专门的保护区中甚至能活得更长。>42 Coal-fired Power PlantsThe invention of the incandescent light bulb by Thomas A. Edison in 1879 created a demand for a cheap, readily    available fuel with which to generate large amounts of electric power. Coal seemed to fit the bill, and it fueled    the earliest power stations (which were set up at the end of the nineteenth century by Edison himself). As more    power plants were constructed throughout the country, the reliance on coal increased. Since the First World War,    coal-fired power plants have accounted for about half of the electricity produced in the United States each year.    In 1986 such plants had a combined generating capacity of 289, 000 megawatts and consumed 83 percent of the nearly    900 million tons of coal mined in the country that year. Given the uncertainty in the future growth of nuclear    power and in the supply of oil and natural gas, coal-fired power plants could well provide up to 70 percent of the    electric power in the United States by the end of the century.Yet, in spite of the fact that coal has long been a source of electricity and may remain one for many years (coal   represents about 80 percent of United States fossil-fuel reserves), it has actually never been the most desirable    fossil fuel for power plants. Coal contains less energy per unit of weight than natural gas or oil; it is difficult to transport, and it is associated with a host of environmental issues, among them acid rain. Since the late 1960's problems of emission control and waste disposal have sharply reduced the appeal of coal-fired power plants. The    cost of ameliorating these environmental problems along with the rising cost of building a facility as large and    complex as a coal-fired power plant, have also made such plants less attractive from apurely economic perspective.Changes in the technological base of coal-fired power plants could restore their attractiveness, however. Whereas    some of these changes are evolutionary and are intended mainly to increase the productivity of existing plants,    completely new technologies for burning coal cleanly are also being developed.火力发电厂托马斯?爱迪生 1879 年发明的白炽灯导致对便宜、易得、可生产大量电能 的燃料的需求。 煤似乎符合这个要求，并成为第一批电厂的燃料(正是爱迪生本人在 19 世 纪末建造了第一批电厂)。 全国到处兴建电厂时，对煤的依赖加深了。 自第一次世界大战 以来，美国每年约有一半的电力是以煤为燃料的电厂提供的。 1986 年这些电厂的总发电能 力达到 28，900 千瓦并且消耗了当年全国开采的九亿吨煤的 83%。 考虑到核能发展以及石 油、天然气供应中的不确定因素，到本世纪末，火力发电厂仍可能为美国提供多达 70%的 电力。 然而，尽管煤长期以来一直是电力的原料之一并且可能会继续如此(煤占美国化石燃 料储量的 80%)，它却不是电厂的理想燃料。 煤的单位能量含量低于石油和天然气，而且会 导致包括酸雨在内的一系列环境问题。 从 1960 年以来，排放控制和垃圾处理的问题极大地 削弱了燃煤电厂的魅力。 由于减轻这些环境问题需要大量资金，而且建造庞大复杂的燃煤 电厂的费用不断上涨，也使得这些电厂从经济角度上不具备吸引力。 改变火力发电厂的基 础技术却可能恢复它们的吸引力。 虽然某些技术改进是渐进的，其目的只是提高现有电厂 的生产率，但人们正在开发全新的清洁燃煤的技术。>43 StatisticsThere were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping orderly records of governmental units (state and statistics come from the same Latin    root status) and a gentlemanly gambling father who relied on mathematics to increase his skill at playing the odds    in games of chance. The influence of the mother on the offspring, statistics, is represented by counting,    measuring, describing, tabulating, ordering, and the taking of censuses -- all of which led to modern descriptive statistics. From the influence of the father came modern inferential statistics, which is based squarely on    theories of probability.Descriptive statistics involves tabulating, depicting and describing collections of data. These data may be    quantitative such as measures of height, intelligence or grade level -- variables that are characterized by an    underlying continuum -- or the data may represent qualitative variables, such as sex, college major or personality    type. Large masses of data must generally undergo a process of summarization or reduction before they are    comprehensible. Descriptive statistics is a tool for describing or summarizing or reducing to comprehensible form    the properties of an otherwise unwieldy mass of data.Inferential statistics is a formalized body of methods for solving another class of problems that present great   difficulties for the unaided human mind. This general class of problems characteristically involve attempts to make predictions using a sample of observations. For example, a school superintendent wishes to determine the proportion of children in a large school system who come to school without breakfast, have been vaccinated for flu, or    whatever. Having a little knowledge of statistics, the superintendent would know that it is unnecessary and inefficient to question each child: the proportion for the entire district could be estimated fairlyaccurately    from a sample of as few as 100 children. Thus, the purpose of inferential statistics is to predict or estimate    characteristics of a population from a knowledge of the characteristics of only a sample of the population.统计学统计方法的早期发展受到两种截然不同的影响。 统计学有一个"母亲"，她致力于井井 有条地记录政府机构的文件(国家和统计学这两个词源于同一个拉丁语词根，status)，还有一 个有绅士般的赌博"父亲"，他依靠数学来提高赌技，以便在几率的游戏中取胜。 "母亲"对 其子女统计学的影响表现在计数、测量、描述、制表、归类和人口普查。 所有这些导致了 现代描述统计学的诞生。 由于"父亲"的影响则产生了完全基于概率论原理的现代推理统计 学。 描述统计学涉及对所收集数据的制表、制图和描述。 这些数据可以是数量性的数据， 如高度、智商、或者是层级性的数据--具有连续性的变量--或数据也可以代表性质变量，如 性别、大学专业或性格类型等等。 数量庞大的数据通常必须经过概括或删减的程序才能为 人所理解。 描述统计学就是这样一个工具，它对极其庞杂的数据进行描述、概括或删减， 使其变成能为人理解的东西。 推理统计学是一套已定形了的方法体系，它解决的是光凭人 脑极难解决的另一类问题。 这类问题的显著特点是试图通过取样调查来作出预测。 例如， 有一位教育督察想知道在一个庞大的学校系统中，不吃早饭就上学的学生、已经做过防感冒 免疫的学生，或其它任何类型的学生占多大比例。 若具备一些统计学的知识，这位督察应 明白，询问每个孩子是没有必要而且没有效率的，只要用 100 个孩子为样本，他就可以相当 精确地得出这些孩子占整个学区的比例了。 因此，推理统计学的目的就是通过了解一个群 体中一些样本的特性，从而对整个群体的特性进行推测和估算。>44   Obtaining   Fresh   Water   from IcebergsThe concept of obtaining fresh water from icebergs that are towed to populated areas and arid regions of the world    was once treated as a joke more appropriate to cartoons than real life. But now it is being considered quite    seriously by many nations, especially since scientists have warned that the human race will outgrow its fresh water supply faster than it runs out of food.Glaciers are a possible source of fresh water that has been overlooked until recently. Three-quarters of the    Earth's fresh water supply is still tied up in glacial ice, a reservoir of untapped fresh water so immense that it    could sustain all the rivers of the world for 1,000 years. Floating on the oceans every year are 7,659 trillion    metric tons of ice encased in 10,000 icebergs that break away from the polar ice caps, more than ninety percent of    them from Antarctica.Huge glaciers that stretch over the shallow continental shelf give birth to icebergs throughout the year. Icebergs    are not like sea ice, which is formed when the sea itself freezes, rather, they are formed entirely on land,    breaking off when glaciers spread over the sea. As they drift away from the polar region, icebergs sometimes move    mysteriously in a direction opposite to the wind, pulled by subsurface currents. Because they melt more slowly than smaller pieces of ice, icebergs have been known to drift as far north as 35 degrees south of the equator in the    Atlantic Ocean. To corral them and steer them to parts of the world where they are needed would not be too difficult.The difficulty arises in other technical matters, such as the prevention of rapid melting in warmer climates and    the funneling of fresh water to shore in great volume. But even if the icebergs lost half of their volume in    towing, the water they could provide would be far cheaper than that produced by desalinization, or removing salt    from water.从冰山中获取淡水 把冰山拖到世界上人口稠密的地区和干旱地带，再从中获取淡水，这个想法曾一度被认为是一个笑话，更适合于卡通画，而非现实生活。 然而现在，许多国家正相当认真地考虑 这件事情，特别是在科学家们发出警告之后。 科学家们认为人类将在耗尽粮食之前首先耗 尽淡水资源。冰川是一个直到最近以前一直被忽视的可能的淡水源。 全球四分之三的淡水 还锁在冰川的冰块中。 冰川就是一个蓄水池，其中未开发的淡水量是如此巨大，足够支持 全世界的江河 1000 年。 每年有 7，659 万亿公吨冰漂流在海洋中。 它们包含在 10，000 座从极地冰帽中断裂出来的冰山中。 这些冰山的 90%以上来自南极。 一年四季里，覆盖 在浅层大陆架上的巨大冰川生成了众多冰山。 冰山和海水的冰不同，后者是海水自身结冰 形成的，而冰山则完全是在陆地上形成的。 当冰川伸展到海水中时，冰山就断裂下来。 当 漂离极地地区时，冰山有时会在底层洋流的推动下颇为神秘地逆风移动。 由于冰山比小块 的冰融化要慢，因此有的冰山在大西洋中向北飘到了赤道以南 35°的地方。 把冰山蓄拦起 来并拖到世界上需要它们的地方将不会太困难。 有困难的是其它的技术事宜。 比如，如何 防止冰山在较暖的气候中迅速融化以及如何把大量的淡水收集到岸上去。 但是，即便在拖 的过程中冰山失去了一半体积，这样做也远比从海水中脱盐取得淡水便宜。>45 The Source of EnergyA summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun; in fact, at the Sun's very center. It is here that is to be found the source of the energy that the Sun constantly pours out into    space as light and heat. This energy is liberated at the center of the Sun as billions upon billions of nuclei of    hydrogen atoms collide with each other and fuse together to form nuclei of helium, and in doing so, release some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun requires that some 600        million tons of hydrogen be converted into helium in the Sun every second. This the Sun has been doing for several    thousands of millions of years. The nuclear energy is released at the Sun's center as high-energy gamma radiation, a form of electromagnetic    radiation like light and radio waves, only of very much shorter wavelength. This gamma radiation is absorbed by    atoms inside the Sun to be reemitted at slightly longer wavelengths. This radiation, in its turn is absorbed and reemitted. As the energy filters through the layers of the solar interior, it passes through the X-ray part of the    spectrum eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape    into space without being absorbed further by solar atoms. A very small fraction of the Sun's light and heat is   emitted in such directions that after passing unhindered through interplanetary space, it hits the Earth.能量的来源概说生命的物理和化学特性必须始于太阳--确切地说，是太阳的核心，而非地球。 能 量来自太阳的核心。 在这里，太阳不停地以光和热的形式向空间倾泻出能量。 数十亿计的 氢原子核在太阳的核心碰撞并且聚变生成氦。 在此过程中一部分原本储存于原子核中的能 量被释放出来。 太阳所产生的光和热需要每秒将六亿吨氢转化为氦。 这样的转化在太阳中已经持续几十亿年了。 核能在太阳的核心被释放为高能的伽马射线。 这是一种电磁射线， 就象光波和无线电波一样，只是波长要短得多。 这种伽玛射线被太阳内的原子所吸收，然 后重新释放为波长稍长一些的光波。 这新的射线再次被吸收，而后释放。 在能量由太阳内 部一层层渗透出来的过程中，它经过了光谱中 X 射线部分，最后变成了光。 在此阶段，能 量到达我们所称的太阳表层，并且离散到空间而不再被太阳原子所吸收。 只有很小一部分 太阳的光和热由此方向释放出来，并且未被阻挡，穿越星空，来到地球。>46 VisionHuman vision like that of other primates has evolved in an arboreal environment. In the dense complex world of a    tropical forest, it is more important to see well than to develop an acute sense of smell. In the course of    evolution members of the primate line have acquired large eyes while the snout has shrunk to give the eye an    unimpeded view. Of mammals only humans and some primates enjoy color vision. The red flag is black to the bull.   Horses live in a monochrome world. Light visible to human eyes however occupies only a very narrow band in the whole electromagnetic spectrum. Ultraviolet rays are invisible to humans though ants and honeybees are sensitive to them. Humans have no direct perception of infrared rays unlike the rattlesnake which has receptors tuned into    wavelengths longer than 0.7 micron. The world would look eerily different if human eyes were sensitive to infrared    radiation. Then instead of the darkness of night, we would be able to move easily in a strange shadowless world    where objects glowed with varying degrees of intensity. But human eyes excel in other ways. They are in fact remarkably discerning in color gradation. The color sensitivity of normal human vision is rarely surpassed even by    sophisticated technical devices. 视觉人类的视觉，和其它灵长目动物的一样，是在丛林环境中进化出来的。 在稠密、复杂 的热带丛林里，好的视觉比灵敏的嗅觉更加重要。 在进化过程中，灵长目动物的眼睛变大， 同时鼻子变小以使视野不受阻碍。 在哺乳类动物中，只有人和一些灵长目动物能够分辨颜 色。 红旗在公牛看来是黑色的，马则生活在一个单色的世界里。 然而，人眼可见的光在整 个光谱中只占一个非常狭窄的频段。人是看不到紫外线的，尽管蚂蚁和蜜蜂可以感觉到。与 响尾蛇不同，人也不能直接感受到红外线。 响尾蛇的感觉器可以感受波长超过 0.7 微米的 光线。 如果人能感受到红外线的话，这世界看上去将十分不同，而且恐怖。 到那时，将与 夜的黑暗相反，我们能轻易地在一个奇异的没有阴影的世界里走动。 任何物体都强弱不等 地闪着光。 然而，人眼在其它方面有优越之处。 事实上，人眼对颜色梯度具有非凡的分辨 能力。 普通人类的视觉感受色彩的灵敏程度，甚至连精密的技术装备都很难超越。  >47 Folk CulturesA folk culture is a small isolated, cohesive, conservative, nearly self-sufficient group that is homogeneous in    custom and race with a strong family or clan structure and highly developed rituals. Order is maintained through    sanctions based in the religion or family and interpersonalrelationships are strong. Tradition is paramount, and     change comes infrequently and slowly. There is relatively little division of labor into specialized duties. Rather, each person is expected to perform a great variety of tasks, though duties may differ between the sexes. Most goods are handmade and subsistence economy prevails. Individualism is weakly developed in folk cultures as are social    classes. Unaltered folk cultures no longer exist in industrialized countries such as the United States and Canada.        Perhaps the nearest modern equivalent in Anglo America is the Amish, a German American farming sect that largely    renounces the products and labor saving devices of the industrial age. In Amish areas, horse drawn buggies still   serve as a local transportation device and the faithful are not permitted to own automobiles. The Amish's central religious concept of Demut "humility", clearly reflects the weakness of individualism    and social class so    typical of folk cultures and there is a corresponding strength of Amish group identity. Rarely do the Amish marry    outside their sect. The religion, a variety of the Mennonite faith, provides the principal mechanism for    maintaining orders.By contrast a popular culture is a large heterogeneous group often highly individualistic and constantly changing.   Relationships tend to be impersonal and a pronounced division of labor exists, leading to the establishment of many specialized professions. Secular institutions of control such as the police and army take the place of religion and family in maintaining order, and a money-based economy prevails. Because of these contrasts, "popular" may be    viewed as clearly different from "folk". The popular is replacing the folk in industrialized countries and in    many developing nations. Folk-made objects give way to their popular equivalent, usually because the popular item    is more quickly or cheaply produced, is easier or time saving to use or leads more prestige to the owner.民间文化民间文化是小型的、孤立的、紧密的、保守的、近乎自给自足的群体，具有同 样的习俗、同样的人种和强有力的家庭或部族结构以及高度发展的宗教仪式。 秩序由宗教 或家庭的约束来维持，成员间的关系非常紧密，传统至高无上，很少有变动且变动缓慢。 劳 动专业分工相对较少。 每个人都要做各类活计，尽管男女两性分工不同。 绝大多数物品是 手工制造的，经济一般为自给自足型。 个人主义和社会阶层在民间文化群体中的发展十分 薄弱。在象美国和加拿大这样的工业化国家里，一成不变的民间文化群体已不复存在了。在 当代美洲的英语区，与民间文化最相似的群体也许算是 Amish。 Amish 是美国的德裔农耕 部落，他们基本上拒绝接受工业时代的大多数产品和节省劳力的设施。 在 Amish 地区，轻 便马车仍是当地的交通工具，信徒们不允许拥有汽车。 Amish 宗教中的核心观念 Demut 即 谦卑典型地反映了在民间文化群中个人主义和阶级的不发达。 而与此同时，Amish 对群体 的认同性却十分强。 Amish 人很少和他们宗派以外的人通婚。 其宗教，作为 Mennonite 信 仰的一种，提供了维护秩序的主要机制。 相反，大众文化是包含不同种族的大群体，通常 高度个性化而且不断在变化。 人际关系冷漠，劳动分工明确，由此产生了许多专门的职业。 世俗的控制机构，比如警察和军队，取代了宗教和家庭来维持秩序，而且实行的是货币经济。 由于存在着这些差异，"大众的"与"民间的"可谓大相径庭。 在工业化国家以及许多发展中 国家里，大众文化正在取代民间文化。 民间制造的物品正让位于大众化产品，这通常是因 为大众化的物品制造起来更快、更便宜，用起来更容易、更方便或者是能给其所有者带来更 多的威望。>48 BacteriaBacteria are extremely small living things. While we measure our own sizes in inches or centimeters, bacterial size is measured in microns. One micron is a thousandth of a millimeter: a pinhead is about a millimeter across.    Rod-shaped bacteria are usually from two to four microns long, while rounded ones are generally one micron in    diameter. Thus if you enlarged a rounded bacterium a thousand times, it would be just about the size of a pinhead.    An adult human magnified by the same amount would be over a mile (1.6 kilometers) tall.Even with an ordinary microscope, you   must look closely to see bacteria. Using a magnification of 100 times, one    finds that bacteria are barely visible as tiny rods or dots. One cannot make out anything of their structure. Using special stains, one can see that some bacteria have attached to them wavy-looking "hairs" called flagella. Others have only one flagellum. The flagella rotate, pushing the bacteria through the water. Many bacteria lack flagella    and cannot move about   by their   own power, while others   can glide   along over surfaces by some little-understood   mechanism.From the bacterial point of view, the world is a very different place from what it is to humans. To a bacterium    water is as thick as molasses is to us. Bacteria are so small that they are influenced by the movements of the   chemical molecules around them. Bacteria under the microscope, even those with no flagella, often bounce about in    the water. This is because they collide with the water molecules and are pushed this way and that. Molecules move    so rapidly that within a tenth of a second the molecules around a bacterium have all been replaced by new ones;    even bacteria without flagella are thus constantly exposed to a changing environment.细菌细菌是极其微小的生物体。 我们用英寸或厘米来测量自己的大小，而测量细菌却 要用微米。 一微米等于千分之一毫米。 针头直径大约一毫米。 棒状细菌通常有 2～4 微米 长，而圆形细菌的直径一般只有 1 微米。 因此，即使你把一个圆形细菌放大 1000 倍，它也 不过一个针头那么大。 可是如果把一个成年人放大 1000 倍，就会变成 1 英里(或 1.6 公里) 多高。 用一般的显微镜观察细菌时，你必须仔细观察才能看见它们。 使用 100 倍的显微镜 时，你会发现细菌不过是隐约可见的小细棒或小点点，而它们的结构你却根本看不出来。 使 用特殊的着色剂后，你会发现有的细菌上长着不少波状的"毛发"即鞭毛，而有的细菌只有一 根鞭毛。 鞭毛的旋转可以推动细菌在水中行进。 不少细菌没有鞭毛，因而不能自己行进。 还有些细菌却能通过某些鲜为人知的机制沿物体表面滑动。 我们所熟知的世界在细菌眼中 完全是另一个样子。 对于细菌来说，水就同糖浆之于人类一样稠密。 细菌是如此的微小， 周围化学分子的一举一动都会对它们产生影响。 在显微镜下，细菌，甚至包括那些没有鞭 毛的细菌，经常在水中跳来跳去。 这是因为它们与水分子相撞后，被弹向各个方向。 分子 移动很迅速，仅 0.1 秒之隔，一个细菌周围的分子就会完全更新。 因此，即使是没有鞭毛 的细菌也暴露在一个不断变化的环境中。>49 SleepSleep is part of a person's daily activity cycle. There are several different stages of sleep, and they too occur    in cycles. If you are an average sleeper, your sleep cycle is as follows. When youfirst drift off into slumber,    your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing    well slow and become quite regular. Your brain waves slow down a bit too, with the alpha rhythm of rather fast    waves predominating for the first few minutes. This is called stage 1 sleep. For the next half hour or so, as you    relax more and more, you will drift down through stage 2 and stage 3 sleep. The lower your stage of sleep, the slower your brain waves will be. Then about 40 to 60 minutes after you lose consciousness you will have reached the deepest sleep of all. Your brain waves will show the large slow waves that are known as the delta rhythm. This is    stage 4 sleep.You do not remain at this deep fourth stage all night long, but instead about 80 minutes after you fall into    slumber, your brain activity level will increase again slightly. The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids as if you were    looking at something occurring in front of you. This period of rapid eye movement lasts for some 8 to 15 minutes    and is called REM sleep. It is during REM sleep period, your body will soon relax again, your breathing will grow    slow and regular once more, and you will slip gently back from stage 1 to stage 4 sleep - only to rise once again    to the surface of near consciousness some 80 minutes later.睡眠睡眠是人每天日常活动循环的一部分。 人的睡眠分几个阶段，而这些阶段也是循环发 生的。 如果你是一个正常的睡眠者，你的睡眠循环会这样进行。 在你开始昏昏入睡时，你 的眼睛会滚动几下，体温略有下降，肌肉放松，呼吸变得缓慢而有节奏。 除了开始几分钟 比较快的α节奏外，脑电波也稍有减缓。 这被称为第一阶段睡眠。 在随后约半小时内，你 进一步放松，进入第二和第三阶段睡眠。 睡眠越深入，脑电波就越缓慢。 大约在开始睡眠 后的 40 到 60 分钟，你将进入沉睡状态。 这时的脑电波表现为巨大的缓波，被称为δ节奏。 这就是第四阶段睡眠。 但你并不是整夜都保持这种沉睡状态。 入睡后约 80 分钟左右，你 的大脑运动水平会再度略有提高。 δ节奏消失，并被脑电波的运动图形取代。 你的眼睛会 在闭着的眼睑下迅速转动，就好象你在看着眼前发生的什么事情。 这种迅速的眼球运动持 续约 8～15 分钟，这一阶段睡眠被称之为快速眼动(REM)睡眠。 在 REM 睡眠阶段，你的肢 体会很快再度放松，呼吸也再次放慢并变得有节奏，你会轻松地从第一阶段滑入第四阶段睡 眠-直到大约 80 分钟后重新接近清醒状态。>50 Cells and TemperatureCells cannot remain alive outside certain limits of temperature, and much narrower limits mark the boundaries of effective functioning. Enzyme systems of mammals and birds are most efficient only within a narrow range around 37 ℃; a departure of a few degrees from this value seriously impairs their functioning. Even though cells can survive wider fluctuations, the integrated actions of bodily systems are impaired. Other animals have a wider tolerance for changes of bodily temperature. For centuries it has been recognized that mammals and birds differ from other animals in the way they regulate body temperature. Ways of characterizing the difference have become more accurate and meaningful over time, but popular terminology still reflects the old division into "warm    blooded" and "cold    blooded" species; warm-blooded included mammals and birds whereas all other creatures were considered cold-blooded. As more species were studied, it became evident that this classification was inadequate. A fence lizard or adesert iguana -- each cold-blooded -- usually has a body temperature only a degree or two below that of humans and so is not cold. Therefore the next distinction was made between animals that maintain a constant body temperature, called homeotherms, and those whose body temperature varies with their environment, called poikilotherms. But this classification also proved inadequate, because among mammals there are many that vary their body temperatures during hibernation. Furthermore, many invertebrates that live in the depths of the ocean never experience a change in the chill of the deep water, and their body temperatures remain constant.细胞与温度 细胞只能在一定的温度范围内存活，而进一步保证它们有效工作的温度范围就更小了。哺乳动物和鸟类的酶系统只能在 37℃左右的很小范围内才能有效工作。 与此相差仅几度的 温度都会大大削弱它们的工作效率。 尽管温度变化更大时细胞仍能存活，但机体系统的整 体运行能力却被削弱了。 其它动物对体温的变化有更强的适应性。 几个世纪以来，人们就 认识到哺乳动物和鸟类调节体温的方式与其它动物不同。 随着时间的推移，人们对这种差 异的描述越来越精确和有意义，但是"暖血动物"和"冷血动物"这一古老的分类方式至今仍在 大众词汇中有所反映。 暖血动物包括哺乳动物和鸟类，其它动物统统被视为冷血动物。 但 是对更多物种进行的研究表明这种分类显然是不适当的。 美洲一种小型蜥蜴和沙漠鬣蜥同 属冷血动物，但实际上它们的体温通常只比人类的体温低 1～2 度，因此并不是真正的冷血。 因此又出现了恒温动物(即保持恒定体温的动物)和变温动物(即体温随外界环境的变化而改 变的动物)这一区分方式。 但这种分类也不恰当。 因为有不少哺乳动物在冬眠期间会改变 体温，而许多生活在深海的无脊椎动物在寒冷的深海水域中体温并不变化，而是恒定的。