31.
(A)The number of visits they receive.
(C) The files they have collected. 　　
(B) The way they store data.
(D)The means they use to get information.

27. (A)How humans are to cope with global warming. 　　(B) How unstable the West Antarctic ice sheet is. 　　(C) How vulnerable the coastal cities are. 　　(D)How polar ice impacts global weather.

28. (A)It collapsed at least once in the past 1.3 million years. 　　(B) It sits firmly on solid rock at the bottom of the ocean. 　　(C) It melted at temperatures a bit higher than those of today. 　　(D)It will have little impact on sea level when it breaks up.

29. (A)The West Antarctic region was once an open ocean. 　　(B) The West Antarctic ice sheet was about 7,000 feet thick. 　　(C) The West Antarctic ice sheet was once floating ice. 　　(D)The West Antarctic region used to be warmer than today. 　　Passage Two

30. Questions 30 to 32 are based on the passage you have just heard. 　　(A)Whether we can develop social ties on the Internet. 　　(B) Whether a deleted photo is immediately removed from the web. 　　(C) Whether our blogs can be renewed daily. 　　(D)Whether we can set up our own websites.

32. (A)When the system is down. (C) When the URL is reused. 　　(B) When new links are set up. (D)When the server is restarted. 　　Passage Three 　　Questions 33 to 35 are based on the passage you have just heard.

33. (A)Some iced coffees have as many calories as a hot dinner. 　　(B) Iced coffees sold by some popular chains are contaminated. 　　(C) Drinking coffee after a meal is more likely to cause obesity. 　　(D)Some brand-name coffees contain harmful substances.

34. (A)Have some fresh fruit. (C) Take a hot shower. 　　(B) Exercise at the gym. (D)Eat a hot dinner.

35. (A)They could enjoy a happier family life. 　　(B) They could greatly improve their work efficiency. 　　(C) Many cancer cases could be prevented. 　　(D)Many embarrassing situations could be avoided. 　　

52. 　　In the early 20th century Americans believed science and technology could _______. (A)solve virtually all existing problems (C) help raise people’s living standards (B) quicken the pace of industrialization (D)promote the nation’s social progress

53. Why did many American scholars become enthusiastic about humanistic studies after World WarⅡ? 　　(A)They wanted to improve their own status within the current education system. 　　(B) They believed the stability of a society depended heavily on humanistic studies. 　　(C) They could get financial support from various foundations for humanistic studies. 　　(D)They realized science and technology alone were no guarantee for a better world.