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.

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.