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.
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.
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.
由于其对人体的影响刺激,一般使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.
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.
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 joints where the thigh 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 corrosive 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.
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.