1. Typical of the grassland1 dwellers2 of the continent is the American antelope3, or pronghorn.
美洲羚羊，或称叉角羚，是该国内典型的草原动物。
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.
1986年看见哈雷慧星的千百万人当中，有多少人可以长寿到足以目睹它在21世纪的回归呢？
3. Anthropologists have discovered that fear, happiness, sadness, and surprise are universally reflected in facial expressions.
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.
因为其对人体的影响刺激,一般用酚作为防腐剂已基本停止.
5. Any profit organizations to survive and ultimately consumers must produce usable or needed products.
任何盈利组织若要存活，最后都需要生产出买家可用或需要的商品。
6. The greater the population there is in a locality, the greater the need there is for water, transportation, and disposal of refuse.
一个地方的人口越多，其对水，交通和垃圾处置的需要就会越大。
7. It is more difficult to write simply, directly, and effectively than to employ flowery but vague expressions that only obscure ones meaning.
简明，直接，有力的写作难于花哨，含混而意义模糊的表达。
10. The knee is the joints4 where the thigh5 bone meets the large bone of the lower leg.
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 corrosive6 action on metals, and the ability to turn certain blue vegetable dyes red.
酸是一种化合物，它在溶于水时具备强烈的气味和对金属的腐蚀性，并且可以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.
Billie Holidays作为一个爵士布鲁斯乐杰出歌手的名声打造在可以赋予歌曲感情深度的能力。
13. Essentially7, a theory is an abstract, symbolic8 representation of what is conceived to be reality.
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.
儿童在能说或能听懂语言之前，很长时间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 cacti9 and sagebrush could live.
受当代灌溉之赐，农作物在原来只有仙人掌和荞属科植物才能存活的地方旺盛的成长。
16. The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them.
机械计时器的进步促进大家寻求更精确的日晷，以便校准机械计时器。
17. Anthropology10 is a science in that anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others.
人类学是一门科学，由于人类学家使用一整套强有力的办法和技术来记录观测结果，而如此记录下来的观测结果是供别人核查的。
18. Fungi11 are important in the process of decay, which returns ingredients to the soil, enhances soil fertility, and decomposes12 animal debris13.
真菌在腐化过程中十分要紧，而腐化过程将化学物质回报于土壤，提升其肥力，并分解动物粪便。
19. When it is struck, a tuning14 fork produces an almost pure tone, retaining its pitch over a long period of time.
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 plentiful15 in the southeastern part of the United States, they are found as far north as Ohio and Illinois.
虽然美洲山河桃树最集中于美国的东南部但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.
用怪罪其他人的方法来解决问题一般被叫做探寻替罪羊。
22. The chief foods eaten in any country depend largely on what grows best in its climate and soil.
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成长得最好。
23. Over a very large number of trials, the probability of an events occurring is equal to the probability that it will not occur.
在很多的实验中，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 density16 of a substance's solid is higher than the density of its liquid.
大部分物质遇冷缩短，所以他们的密度在固态时高于液态。
25. The mechanism17 by which brain cells store memories is not clearly understood.
大脑细胞储存记忆的机理并不为人了解。