28. I _______ give you an answer tomorrow. I promise!

A. must 　　　　　　　 B. will 　　　　　　　　 C. may 　　　　　　　　 D. shall

27. You _______ the trees. Look, it is raining now.

A. mustn't have watered 　　　　　　　　　　 B. needn't have watered

C. could have watered 　　　　　　　　　　　 D. might have watered

26. Mr. Baker, a number of students want to see you. _____ they wait here or outside?

A. Should 　　　　　　 B. Will 　　　　　　　　 C. Shall 　　　　　　　 D. Are

25. I wonder how he _______ that to the teacher.

A. dare to say 　　　 B. dare saying 　　　 C. not dare say 　　 D. dared say

24. He didn't do well in the exam. He _______ hard at his lessons.

A. must have worked 　　　　　 B. ought to have worked

C. would have worked 　　　　 D. has worked

23. This pen looks like mine, yet it isn't. Whose it _______ be?

A. must 　　　　　　　 B. can 　　　　　　　　 C. may 　　　　 D. might

22. He must have finished his homework, _______ he?

A. mustn't 　　　　　　 B. didn't 　　　　　　　　　　 C. needn't 　　 D. hasn't

21. I wish to go home now, _______ I?

A. may 　　　　　　　　 B. can't 　　　　　　　　 C. must 　　　　 D. do

20. I _______ a little earlier, but I met a friend of mine on the way.

A. may come 　　　　　　　 B. may have come　 C. could have come 　　 D. must have come

19. The taxi ____ only hold six passengers. It is full. You _______ take the next one.

A. may...may 　　　　　　　 B. can...may