21. It is reported that a (n) _________ of accidents has occurred at that crossroads.

A. series B. lot C. number D. amount

22. If someone is in the United States for good, it means he is there _________.

A. to do good B. temporarily C. to rest well D. permanently

23. Please let us have more time, _________.

A. shall we B. will you C. won't D. Don't you

24. There is no hurry. You can take your time _________ those exercises.

A. doing B. to do C. done D. to be doing

25. He spoke English so well that I took it _________ that he was an American.

A. for granted B. as true C. for certain D. as such

26. _________ we need air and water, so we need criticism and self-criticism.

A. Even though B. So long C. Just as D. Now that

27. Children are always curious _________ everything they see.

A. to B. for C. on D. about

28. Anyone, rich or poor, old or young, sick or _________ can follow a favorite hobby.

A. well B. good C. fine D. happy

29. It's desired that she _________ to teach us at least twice a week.

A. ***es B. will ***e C. ***e D. may ***e

30. _________, I should ask them some questions.

A. Should they ***e to us B. If they ***e to us

C. Were they ***e to us D. Had they ***e to us

答案：

21-25 ADBAA 26-30 CDACA