55. I missed the last bus, so I ______ go home on foot.

　　　　 A. must　　　　 B. have to　　　　 C. may　　　　　 D. had to

54. You must be a writer,______ ?

　　　　 A. mustn't you　 B. didn't you　　　 C. don't you　　 D. must you

53. -- Please don't make a noise.　 -- ______ . I'll be as quiet as a mouse.

　　　　 A. Yes, I won't B. No, I won't　　 C. No, I will　　 D. Yes, I will

52. -- Could I borrow your dictionary?　 -- Yes, of course you _______.

　　　　 A. might　　　 B. will　　　　　　 C. can　　　　　 D. should

51.- May I stop here?　 -- No, you ______.

　　　　 A. mustn't　　 B. might not　　　　 C. needn't　　　 D. won't

50. With so much work on hand, you ______ to see the game last night.

　　　　 A. mustn't go B. shouldn't go C. couldn't have gone　 D. shouldn't have gone

49. The plant is dead. I _______ it more water.

　　　　 A. will give　 B. would have given　 C. must give　 D. should have given

48. Please open the window, ______?

　　　　 A. can't you　　 B. aren't you　　　 C. do you　　　 D. will you

47. My idea is that we _______ to our plan.

　　　　 A. must stick　 B. ought to stick　 C. should stick D. will stick

46. It is necessary that we ______ a foreign language.

　　　　 A. must master　 B. ought to master C. master　　　　 D. should master