42. What is the disadvantage of the experimental version of the device?

　　 A. It is too heavy for the walker to bear.

　　 B. It is too complex for people to use.

　　 C. It will slow down one's walking speed.

　　 D. It is too dear for most people to afford.

41. The second paragraph mainly talks about _______.

　 　 A. who developed the device

　 　 B. how the device works

　 　 C. several possible uses for the devices

　 　 D. how much electricity the device can produce

39．a1though/ though．由前后两个分句的逻辑意义可知填表示“尽管，虽然”的连词。

38．everything．everything在原因状语从句中作主语，表示“一切、所有事情”。

37．fewer．指在“人们在许多方面具有相似观点的社会”较在“不同人混合的社会里”，人们觉得有必要改变的机会“更少”。

36．All．指上述提到的“所有”这些因素都会促使社会变化。

35．mixed．因societies与mix是被动关系，用动词的－ed形式作定语，表示“混合的”。

34．with．指“具有”不同信仰的群体或组织。

33．disagreements．在there are后与ideas并列一定是名词，且也要用复数表示“不同意见”。