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　　第1篇 Researchers Discover Why Humans Began Walking Upright

　　31. Which NOT A Many people question the simple human activities of walking and carrying items.

　　32. Dr. Richmond conducted the experiment with the purpose of finding B What made our ancestors walk upright.

　　33. Kyoto,Universitry’s study discovered that chimpanzees C liked coula nuts better than oil palm nuts.

　　34. Why did the chimpanzees walk on two limbs during Kyoto University's experiment? D Because they wanted to carry more nuts with two free limbs.

　　35. What can we infer from the reading passage? D Human walking on two legs developed as a means of survival.

　　第2篇 Ants Have Big Impact on Environment as "Ecosystem Engineers"

　　36 .Why are ants compared to ecosystem engineers?

　　C Because their activity affects the environment.

　　37. As predators, ants

　　A prey on small as well as large animals.

　　38. Dir Sanders' study centered on how ants

　　D produce such a big impact on the environment.

　　39. What does paragraph 6 tell us?

　　B Ants bring about a positive influence to an area when their population is small.

　　40. What still remains unclear about ants, according to the last paragraph?

　　C How do human activities affect ants' influence on a given ecosystem?