1. Typical of the grassland dwellers of the continent is the American antelope, or pronghorn.
1.美洲羚羊，或称叉角羚，是该大陆典型的草原动物。 
2. Of the millions who saw Haley's comet in 1986, how many people will live long enough to see it return in the twenty-first    century.
2. 1986年看见哈雷慧星的千百万人当中，有多少人能够长寿到足以目睹它在二十一世纪的回归呢？
3. Anthropologists have discovered that fear, happiness, sadness, and surprise are universally reflected in facial expressions.
3.人类学家们已经发现，恐惧，快乐，悲伤和惊奇都会行之于色，这在全人类是共通的。
4. Because of its irritating effect on humans, the use of phenol as a general antiseptic has been largely discontinued.
4.由于苯酚对人体带有刺激性作用，它基本上已不再被当作常用的防腐剂了。
5. In group to remain in existence, a profit-making organization must, in the long run, produce something consumers consider useful or desirable.
5.任何盈利组织若要生存，最终都必须生产出消费者可用或需要的产品。
6. The greater the population there is in a locality, the greater the need there is for water, transportation, and disposal of refuse.
6.一个地方的人口越多，其对水，交通和垃圾处理的需求就会越大。
7. It is more difficult to write simply, directly, and effectively than to employ flowery but vague expressions that only obscure one's meaning.
7.简明，直接，有力的写作难于花哨，含混而意义模糊的表达。
8. With modern offices becoming more mechanized, designers are attempting to personalize them with warmer, less severe interiors.
8.随着现代办公室的日益自动化，设计师们正试图利用较为温暖而不太严肃的内部装饰来使其具有亲切感。
9. The difference between libel and slander is that libel is printed while slander is spoken.
9.诽谤和流言的区别在于前者是书面的，而后者是口头的。
10. The knee is the joints where the thigh bone meets the large bone of the lower leg.
10.膝盖是大腿骨和小腿胫的连接处。
11. Acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on metals, and the ability to turn certain blue vegetable dyes red.
11.酸是一种化合物，它在溶于水时具有强烈的气味和对金属的腐蚀性，并且能够使某些蓝色植物染料变红。
12. Billie Holiday's reputation as a great jazz-blues singer rests on her ability to give emotional depth to her songs.
12. Billie Holiday's作为一个爵士布鲁斯乐杰出歌手的名声建立在能够赋予歌曲感情深度的能力。
13. Essentially, a theory is an abstract, symbolic representation of what is conceived to be reality. 
13.理论在本质上是对认识了的现实的一种抽象和符号化的表达。 
14. Long before children are able to speak or understand a language, they communicate through facial expressions and by making noises. 
14.儿童在能说或能听懂语言之前，很久就会通过面部表情和靠发出噪声来与人交流了。
15. Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live. 
15.受当代灌溉(技术设施)之赐，农作物在原来只有仙人掌和荞属科植物才能生存的地方旺盛的生长。
16. The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them. 
16.机械计时器的发展促使人们寻求更精确的日晷，以便校准机械计时器。
17. Anthropology is a science in that anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others. 
17.人类学是一门科学，因为人类学家采用一整套强有力的方法和技术来记录观测结果，而这样记录下来的观测结果是供他人核查的。
18. Fungi are important in the process of decay, which returns ingredients to the soil, enhances soil fertility, and decomposes animal debris. 
18.真菌在腐化过程中十分重要，而腐化过程将化学物质回馈于土壤，提高其肥力，并分解动物粪便。
19. When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time. 
19.音叉被敲击时，产生几乎纯质的音调，其音量经久不衰。
20. Although pecans are most plentiful in the southeastern part of the United States, they are found as far north as Ohio and Illinois. 
20.虽然美洲山河桃树最集中于美国的东南部但是在北至俄亥俄州及伊利诺州也能看见它们。
21. Eliminating problems by transferring the blame to others is often called scape-goating. 
21.用怪罪别人的办法来解决问题通常被称为寻找替罪羊。
22. The chief foods eaten in any country depend largely on what grows best in its climate and soil. 
22.一个国家的主要食物是什么，大体取决于什么作物在其天气和土壤条件下生长得最好。
23. Over a very large number of trials, the probability of an event's occurring is equal to the probability that it will not occur. 
23.在大量的实验中，某一事件发生的几率等于它不发生的几率。
24. Most substance contract when they freeze so that the density of a substance's solid is higher than the density of its liquid. 
24.大多数物质遇冷收缩，所以他们的密度在固态时高于液态。
25. The mechanism by which brain cells store memories is not clearly understood. 
25.大脑细胞储存记忆的机理并不为人明白。
26. By the middle of the twentieth century, painters and sculptors in the United States had begun to exert a great worldwide influence over art. 
26.到了二十一世纪中叶，美国画家和雕塑家开始在世界范围内对艺术产生重大影响。
27. In the eastern part of New Jersey lies the city of Elizabeth, a major shipping and manufacturing center.
27.伊丽莎白市，一个重要的航运和制造业中心，坐落于新泽西州的东部。
28. Elizabeth Blackwell, the first woman medical doctor in the United States, founded the New York Infirmary, an institution that has always had a completely female medical staff.
28. Elizabeth Blackwell，美国第一个女医生，创建了员工一直为女性纽约诊所。
29. Alexander Graham Bell once told his family that he would rather be remembered as a teacher of the deaf than as the inventor of the telephone.
29. Alexander Graham Bell曾告诉家人，他更愿意让后人记住他是聋子的老师，而非电话的发明者。
30. Because its leaves remain green long after being picked, rosemary became associated with the idea of remembrance.
30.采摘下的迷迭香树叶常绿不衰，因此人们把迷迭香树与怀念联系在一起。
31. Although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to withstand considerable impact.
31.骨头看起来是脆硬的，但它也有一定的弹性，使得骨骼能够承受相当的打击。
32. That xenon could not FORM chemical compounds was once believed by scientists.
32.科学家曾相信：氙气是不能形成化合物的。
33. Research into the dynamics of storms is directed toward improving the ability to predict these events and thus to minimize damage and avoid loss of life.
33.对风暴动力学的研究是为了提高风暴预测从而减少损失，避免人员伤亡。
34. The elimination of inflation would ensure that the amount of money used in repaying a loan would have the same value as the amount of money borrowed.
34.消除通货膨胀应确保还贷的钱应与所贷款的价值相同。
35. Futurism, an early twentieth-century movement in art, rejected all traditions and attempted to glorify contemporary life by emphasizing the machine and motion.
35.未来主义，二十世纪早期的一个艺术思潮。拒绝一切传统，试图通过强调机械和动态来美化生活。
36. One of the wildest and most inaccessible parts of the United States is the Everglades where wildlife is abundant and largely protected.
36. Everglades是美国境内最为荒凉和人迹罕至的地区之一，此处有大量的野生动植物而且大多受(法律)保护。
37. Lucretia Mott's influence was so significant that she has been credited by some authorities as the originator of feminism in the United States.
37. Lucretia Mott's的影响巨大，所以一些权威部门认定她为美国女权运动的创始人。
38. The activities of the international marketing researcher are frequently much broader than those of the domestic marketer.
38.国际市场研究者的活动范围常常较国内市场研究者广阔。
39. The continental divide refers to an imaginary line in the North American Rockies that divides the waters flowing into the Atlantic Ocean from those flowing into the Pacific.
39.大陆分水岭是指北美洛矶山脉上的一道想象线，该线把大西洋流域和太平洋流域区分开来。
40. Studies of the gravity field of the Earth indicate that its crust and mantle yield when unusual weight is placed on them.
40.对地球引力的研究表明，在不寻常的负荷之下地壳和地幔会发生位移。
41. The annual worth of Utah's manufacturing is greater than that of its mining and farming combined.
41.尤它州制造业的年产值大于其工业和农业的总和。
42. The wallflower is so called because its weak stems often grow on walls and along stony cliffs for support.
42.墙花之所以叫墙花，是因为其脆弱的枝干经常要靠墙壁或顺石崖生长，以便有所依附。
43. It is the interaction between people, rather than the events that occur in their lives, that is the main focus of social psychology.
43.社会心理学的主要焦点是人与人之间的交往，而不是他们各自生活中的事件。
44. No social crusade aroused Elizabeth Williams' enthusiasm more than the expansion of educational facilities for immigrants to the United States.
44.给美国的新移民增加教育设施比任何社会运动都更多的激发了Elizabeth Williams的热情。
45. Quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.
45.典型的鹌鹑都长有短而圆的翅膀，凭此他们可以在受惊时一跃而起，飞离它们的躲藏地。
46. According to anthropologists, the earliest ancestors of humans that stood upright resembled chimpanzees facially, with sloping foreheads and protruding brows.
46.根据人类学家的说法，直立行走的人的鼻祖面部轮廓与黑猩猩相似，额头后倾，眉毛突出。
47. Not until 1866 was the fully successful transatlantic cable finally laid.
47.直到1866年第一条横跨大西洋的电缆才完全成功的架通。
48. In his writing, John Crowe Ransom describes what he considers the spiritual barrenness of society brought about by science and technology.
48. John Crowe Ransom在他的著作中描述了他认为是由科学技术给社会带来的精神贫困。
49. Children with parents whose guidance is firm, consistent, and rational are inclined to possess high levels of self-confidence.
49.父母的教导如果坚定，始终如一和理性，孩子就有可能充满自信。
50. The ancient Hopewell people of North America probably cultivated corn and other crops, but hunting and gathering were still of critical importance in their economy.
50.北美远古的Hopewell人很可能种植了玉米和其他农作物，但打猎和采集对他们的经济贸易仍是至关重要的。
51. Using many symbols makes it possible to put a large amount of inFORMation on a single map.
51.使用多种多样的符号可以在一张地图里放进大量的信息。
52. Anarchism is a term describing a cluster of doctrines and attitudes whose principal uniting feature is the belief that government is both harmful and unnecessary.
52.无政府主义这个词描述的是一堆理论和态度，它们的主要共同点在于相信政府是有害的，没有必要的。
53. Probably no man had more effect on the daily lives of most people in the Untied States than did Henry Ford a pioneer in automobile production.
53.恐怕没有谁对大多数美国人的日常生活影响能超过汽车生产的先驱亨利.福特。
54. The use of well-chosen nonsense words makes possible the testing of many basic hypotheses in the field of language learning.
54.使用精心挑选的无意义词汇，可以检验语言学科里许多基本的假定。
55. The history of painting is a fascinating chain of events that probably began with the very first pictures ever made.
55.优化历史是由一连串的迷人事件组成，其源头大概可以上溯到最早的图画。
56. Perfectly matched pearls, strung into a necklace, bring a far higher price than the same pearls told individually.
56.相互般配的珍珠，串成一条项链，就能卖到比单独售出好得多的价钱。
57. During the eighteenth century, Little Turtle was chief of the Miami tribe whose territory became what is now Indiana and Ohio.
57.十八世纪时，"小乌龟"是迈阿密部落的酋长，该部落的地盘就是今天的印第安那州和俄亥俄州。
58. Among almost seven hundred species of bamboo, some are fully grown at less than a foot high, while others can grow three feet in twenty-four hours.
58.在竹子的近七百个品种中，有的全长成还不到一英尺，有的却能在二十四小时内长出三英尺。
59. Before staring on a sea voyage, prudent navigators learn the sea charts, study the sailing directions, and memorize lighthouse locations to prepare themselves for any conditions they might encounter.
59.谨慎的航海员在出航前，会研究航向，记录的灯塔的位置，以便对各种可能出现的情况做到有备无患。
60. Of all the economically important plants, palms have been the least studied.
60.在所有的经济作物中，棕榈树得到的研究最少。
61. Buyers and sellers should be aware of new developments in technology can and does affect marketing activities.
61.购买者和销售者都应该留意技术的新发展，原因很简单，因为技术能够并且已经影响着营销活动。
62. The application of electronic controls made possible by the microprocessor and computer storage have multiplied the uses of the modern typewriter.
62.电脑储存和由于电子微处理机得以实现的电控运用成倍的增加了现代打字机的功能。
63. The human skeleton consists of more than two hundred bones bound together by tough and relatively inelastic connective tissues called ligaments.
63.人类骨骼有二百多块骨头组成，住些骨头石油坚韧而相对缺乏弹性的，被称为韧带的结蒂组连在一起。
64. The pigmentation of a pearl is influenced by the type of oyster in which it develops and by the depth, temperature, and the salt content of the water in which the oyster lives.
64.珍珠的色泽受到作为其母体牡蛎种类及牡蛎生活水域的深度，温度和含盐度的制约。
65. Although mockingbirds superbly mimic the songs and calls of many birds, they can nonetheless be quickly identified as mockingbirds by certain aural clues.
65.尽管模仿鸟学很多种鸟的鸣叫声惟妙惟肖，但人类还是能够依其声音上的线索很快识别它们。
66. Not only can walking fish live out of water, but they can also travel short distances over land.
66.鲇鱼不仅可以离开水存活，还可以在岸上短距离移动。
67. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible.
67.科学家不知道恐龙为何绝种了，但是一些理论推断是地理，气候和海平面的变化造成的。
68. The science of horticulture, in which the primary concerns are maximum yield and superior quality, utilizes inFORMation derived from other sciences.
68.主要目的在于丰富和优质的农艺学利用了其他科学的知识。
69. Snow aids farmers by keeping heart in the lower ground levels, thereby saving the seeds from freezing.
69.雪对农民是一种帮助，因为它保持地层土壤的温度，使种子不致冻死。
70. Even though the precise qualities of hero in literary words may vary over time, the basic exemplary function of the hero seems to remain constant.
70.历代文学作品中的英雄本色虽各有千秋，但其昭世功力却是恒古不变的。
71. People in prehistoric times created paints by grinding materials such as plants and clay into power and then adding water.
71.史前的人们制造颜料是将植物和泥土等原料磨成粉末，然后加水。
72. Often very annoying weeds, goldenrods crowd out less hardy plants and act as hosts to many insect pests.
72.黄菊花通常令人生厌，它挤走不那么顽强的植物，并找来很多害虫。
73. Starting around 7000 B.C., and for the next four thousand years, much of the Northern Hemisphere experienced temperatures warmer than at present.
73.大约从公元前七千年开始，在四千年当中，北半球的温度比现在高。
74. When Henry Ford first sought financial backing for making cars, the very notion of farmers and clerks owning automobiles was considered ridiculous.
74.当亨利.福特最初制造汽车为寻求资金支持时，农民和一般职员也能拥有汽车的想法被认为是可笑的。
75. Though once quite large, the population of the bald eagle across North America has drastically declined in the past forty years.
75.北美秃头鹰的数量一度很多，但在近四十年中全北美的秃头鹰数量急剧下降。
76. The beaver chews down trees to get food and material with which to build its home.
76.水獭啃倒树木，以便取食物并获得造窝的材料。
77. Poodles were once used as retrievers in duck hunting, but the American Kennel Club does not consider them sporting dogs because they are now primarily kept as pets.
77.长卷毛狗曾被用作猎鸭时叼回猎物的猎犬，但是美国Kennel Club却不承认它们为猎犬，因为它们现在大多数作为宠物饲养。
78. As a result of what is now know in physics and chemistry, scientists have been able to make important discoveries in biology and medicine.
78.物理学和化学的一个成果是使得科学家们能在生物学和医学上获得重大发现。
79. The practice of making excellent films based on rather obscure novels has been going on so long in the United States as to constitute a tradition.
79.根据默默无闻的小说制作优秀影片在美国由来已久，已经成为传统。
80. Since the consumer considers the best fruit to be that which is the most attractive, the grower must provide products that satisfy the discerning eye.
80.因为顾客认为最好的水果应该看起来也是最漂亮的，所以种植者必须提供能满足挑剔眼光的产品。
81. Television the most pervasive and persuasive of modern technologies, marked by rapid change and growth, is moving into a new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world.
81.电视，这项从迅速变化和成长为标志的最普及和最有影响力的现代技术，正在步入一个新时代，一个极为成熟和多样化的时代，这将重塑我们的生活和世界。
82. Television is more than just an electronics; it is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.
82.电视不仅仅是一件电器；它是表达的手段和交流的载体并因此成为联系他人的有力工具。
83. Even more shocking is the fact that the number and rate of imprisonment have more than doubled over the past twenty years, and recidivism------that is the rate for re-arrest------is more than 60 percent.
83.更让人吃惊的事实是监禁的数目和比例在过去的二十年中翻了一番还有余，以及累犯率——即再次拘押的比例——为百分之六十强。
84. His teaching began at the Massachusetts Institute of Technology, but William Rainey Harper lured him to the new university of Chicago, where he remained officially for exactly a generation and where his students in advanced composition found him terrifyingly frigid in the classroom but sympathetic and understanding in their personal conferences.
84.他的教书生涯始于麻省理工学院，但是William Rainey Harper把他吸引到了新成立的芝加哥大学。他在那里正式任职长达整整一代人的时间。他的高级作文课上的学生觉得他在课上古板得可怕，但私下交流却富有同情和理解。
85. The sloth pays such little attention to its personal hygiene that green algae grow on its coarse hair and communities of a parasitic moth live in the depths of its coat producing caterpillars which graze on its mouldy hair. Its muscles are such that it is quits incapable of moving at a speed of over a kilometer an hour even over the shortest distances and the swiftest movement it can make is a sweep of its hooked arm.
85.树獭即不讲究卫生，以至于它粗糙的毛发上生出绿苔，成群的寄生蛾生长在它的皮毛深处，变成毛毛虫，并以它的脏毛为食。她的肌肉不能让他哪怕在很短的距离以内以每小时一公里的速度移动。它能做的最敏捷的动作就是挥一挥它弯曲的胳膊。
86. Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as way and glass, so skillfully that they can scarcely be distinguished from natural flowers.
86.人造花卉即可用于科学目的，也可用于装饰目的，它们可以用各种各样的材料制成，臂如蜡和玻璃；其制作如此精巧，几乎可以以假乱真。
87. Three years of research at an abandoned coal mine in Argonne, Illinois, have resulted in findings that scientists believe can help reclaim thousands of mine disposal sites that scar the coal-rich regions of the United States.
87.在伊利诺州Angonne市的一个废弃煤矿的三年研究取得了成果，科学家们相信这些成果可以帮助改造把美国产煤区弄得伤痕累累的数千个旧煤场。
88. When the persuading and the planning for the western railroads had finally been completed, the really challenging task remained: the dangerous, sweaty, backbreaking, brawling business of actually building the lines.
88.当有关西部铁路的说服和规划工作终于完成后，真正艰难的任务还没有开始；即危险，吃力，需要伤筋动骨和吵吵嚷嚷的建造这些铁路的实际工作。
89. Because of the space crunch, the Art Museum has become increasingly cautious in considering acquisitions and donations of art, in some cases passing up opportunities to strengthen is collections.
89.由于空间不足，艺术博物馆在考虑购买和接受捐赠的艺术品是越来越慎重，有些情况下放弃其进一步改善收藏的机会。
90. The United States Constitution requires that President be a natural-born citizen, thirty-five years of age or older, who has lived in the United States for a minimum of fourteen years.
90.美国宪法要求总统是生于美国本土的公民，三十五岁以上，并且在美国居住了至少十四年。
91. Arid regions in the southwestern United States have become increasingly inviting playgrounds for the growing number of recreation seekers who own vehicles such as motorcycles or powered trail bikes and indulge in hill-climbing contests or in caving new trails in the desert.
91.美国西部的不毛之地正成为玩耍的地方，对越来越多拥有摩托车或越野单车类车辆的，喜欢放纵于爬坡比赛或开辟新的沙漠通道的寻欢作乐者具有不断增长的吸引力。
92. Stone does decay, and so tools of long ago have remained when even the bones of the man who made them have disappeared without trace.
92.石头不会腐烂，所以以前的(石器)工具能保存下来，虽然它们的制造者已经消失的无影无踪。
93. Insects would make it impossible for us to live in the world; they would devour all our crops and kill our flocks and herds, if it were not for the protection we get from insect-eating animals.
93.昆虫就将会使我们无法在这个世界上居住；如果我们没有受到以昆虫为食的动物的保护，昆虫就会吞嚼掉我们所有的庄稼并杀死我们饲养的禽兽。 　　94. It is true that during their explorations they often faced difficulties and dangers of the most perilous nature, equipped in a manner which would make a modern climber shudder at the thought, but they did not go out of their way to court such excitement.
94.确实，他们在探险中遇到了极具威胁性的困难和危险，而他们的装备会让一个现代登山者想一想都会浑身颤栗。不过他们并不是刻意去追求刺激的。
95. There is only one difference between an old man and a young one: the young man has a glorious future before him and old one has a splendid future behind him: and maybe that is where the rub is.
95.老人和年轻人之间只有一个区别：年轻人的前面有辉煌的未来，老年人灿烂的未来却已在它们身后。这也许就是困难之所在。
96. I find young people exciting. They have an air of freedom, and they have not a dreary commitment to mean ambitions or love comfort. They are not anxious social climbers, and they have no devotion to material things.
96.我们位年强人振奋。它们带有自由的气息，他们不会为狭隘的野心和贪婪享受而孜孜以求。他们不是焦虑的向上爬的人，他们不会对物质性的东西难舍难分。
97. I am always amazed when I hear people saying that sport creates goodwill between the nations, and that if only the common peoples of the world could meet one another at football or cricket, they would have no inclination to meet on the battlefield.
97.每次我听说体育运动能够在国家间建立起友好感情，说世界各地的普通人只要能在足球场或板球场上相遇就会没有兴趣在战场上相遇的话，我都倍感诧异。
98. It is impossible to say simply for the fun and exercise: as soon as the question of prestige arises, as soon as you feel that you and some larger unit will be disgraced if you lose, the most savage combative instincts are around.
98.没有可能仅仅为了娱乐或锻炼而运动：一旦有了问题，一旦你觉得你输了你和你所属团体会有失体面时，你最野蛮的好斗本能就会被激发出来。
99. It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles------or locate flying insects on which they feed. This echo-location in bats is often compared with radar, the principle of which is similar.
99.人们已经发现，某些蝙蝠发出尖叫声并靠接受回响来锁定和避免障碍物——或者找到它们赖以为生的昆虫。蝙蝠这种回响定位法常拿来和原理与之很相近似的雷达相比。
100. As the time and cost of making a clip drop to a few days and a few hundred dollars, engineers may soon be free to let their imaginations soar without being penalized by expensive failure.
100.随着芯片制造时间和费用降低到了几天和几百美元，工程师们可能很快可以任他们的想象驰骋而不会被昂贵的失败所惩罚。