30. It was the early 2000s ______ mobile phones were widely used in China, __________ it was considered the patent of the rich.

　 A. that; in which　 B. when; before which　 C. that; after which　 D. when; in where

29. –The plane is due to take off at 7:50 from the airport. ______ we fail to arrive there in time?

　 --Try to take another flight then.’

　 A. What if　　 B. As if　　 C. Even if　 D. Only if

28. Had they been warned of the possible danger, they ______.

　 A. may have escaped　 B. could have escaped　 C. must have escaped　 D. can have escaped

27. As the famous expert ______, the secret _____happiness is to think about positive things and stay optimistic.

　 A. retells; on　　 B. reminds; to　 C. remarks; of　　 D. respects; in

26. –Who is singing and dancing in the gym now?

　 --_______ the students from the art department.

A. They are　 B. It is　　 C. There are　 D. That is

25. _______, and the Iraqis can get real peace.

　 A. If the American soldiers leave Iraq.　　　　 B. Driving the American soldiers out of Iraq.

　 C. Drive the American soldiers out of Iraq.　　 D. The American soldiers leave Iraq.

24. –Must I do the math exercise step by step?

　 --Of course. You can never be _______careful with that.

　 A. too　　 B. enough　 C. so　　 D. very

23. –Jack, you have earned so much in such a short time!

　 --Yes, I have. But I am still _______, in terms of fortune, than you.

　 A. better off　　 B. more worse off　 C. less well off　 D. less badly off

22. The flood and the infection ________ brought along really made the4 villagers suffer a lot.

　 A. it　 B. that　 C. which　 D. what

21．This is our contribution to ________ world of the 21th century, _____ world of independence and mutual understanding.

　 A. the; /　　 B. /; a　 C. a; the　　 D. the; a