1. 1) F 2) F 3) F 4) T 5) T 6) F 7) F 8) T 9) F 10) T

2. 1) C 2) A 3) B 4) A 5) D 6) C

3. 1) 人类起源的故事把我们带回久远以前的、与我们今天所认识的迥然不同的世界。

2）一些小树便停止生长，无望长大。

3）我们那些远古祖先在这片崎岖荒芜的土地上为自己开辟出一条生路，顶着风险存活下来。

4）人也许跑不过野兽，但比任何野兽都能走。

5）这七种天赋帮助了冰川时期的人们，使他们在艰难的生活环境中未受许多危险的袭扰。

1. 1) remarkable 2) flexible 3) complicated 4) hostile 5) exhausted 6) slender 7)fierce

8) swift 9) feebler 10) erect

2. 1) on 2) from 3) in; by 4) by 5) in 6) from 7) on 8) with 9) on 10) in

3. 1) Thomas Jefferson, the third president of the United States, played a leading role in the revolution know as the War of Independence.

2) The police asked him to explain in detail why he happened not to be on the spot when the accident happened.

3) Modern archaeologists estimate that even today, with truck to transport rocks, in will take years to accomplish such a big project as the Great Pyramid in ancient Egypt.

4) The investigation shows that the government is unlikely to survive the next election.

5) Compared with an ocean, even the greatest lake on the earth is very small.

6) She admitted she had spoken to them, and what’s more, had told them about our secret discussions.

Key to lesson 18 1. 1)T 2)F 3)T 4)F 5)T 6)F 7)F 8)T

2. 1)B 2)C 3)C 4)A 5)D 6)B

3. 1)当他想起他留在房子里的那具死尸，他居然很镇静

2）邓恩知道斯特郎有些值钱的旧金器，因为他是珠宝商，经常收购这些东西，然后回炉

3）他毫不犹豫地用这把旧刀子捅死了斯特恩

4）想到还要去一趟斯特朗家，使他感到恐慌万分。

5）然后他想到了监狱。他将在监狱里度过余生。想到这些，他只得再次出门来到街上。

6）他觉得在每个拐角处他都看到一些奇怪的影子。有一次他看到地上一张纸几乎大叫起来，猛一看这张纸活像一具死尸