English part.

1. Essentially, a theory is an abstract, symbolic representation of what is conceived to be reality.
2. Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live.
3. Ahthropologists have discovered that fear, happiness, sadness, and surprise are universally reflected in facial expression.
4. 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.
5. The greater the population there is in a locality, the greater the need there is for water, transportation, and disposal of refuse.

要好好学英语…把这本书的句子部分背一遍，在博客把中分英文分开打以便方便对照记忆。

1. 理论在本质上是对人们构想的现实的一种抽象和符号化的表示。
2. 受当代灌溉设施之赐，在原来只有仙人掌和灌木蒿才能生存的地方，现在农作物也生长茂盛。
3. 人类学家已经发现，恐惧、快乐、悲伤和惊奇会反映在面部表情上，这在全人类是共通的。
4. 1986年看见哈雷彗星的千百万人当中，有多少人能够长寿到足以目睹它在21世纪的回归呢？
5. 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。