54.　 Please don’t get worried. The guide will show you ______ the park now.

A. out　　　 B. about　　　 C. for　　　 D. on

53.　 ______ come on time tomorrow, or you won’t be allowed to enter the meeting room.

A. Do　　　 B. Will　　　 C. Must　　 D. Be sure

52.　 An awful accident ______, however, occur the other day.

A. does　　 B. did　　 C. has to　　 D. had to

51.　 I told Sally how to get here, but perhaps I ______ for her.

A. had to write it out　　　　　 B. must have written it out

C. should have written it out　　 D. ought to write it out

50.　 Oh, I’m not feeling well in the stomach, I ______ so much fried chicken just now.’

A. shouldn’t eat　 B. mustn’t have eaten　 C. shouldn’t have eaten　 D. mustn’t eat

49.　 If no one ______ the phone at home, ring me at work.

A. returns　　 B. receives　　 C. replies　　 D. answers

48.　 Only in this way ______ to make improvement in the operating system.

A. you can hope　 B. you did hope　 C. can you hope　 D. did you hope

47.　 I failed in the final examination last term and only then ______ the importance of studies.

A. I realized　　 B. I had realized　　 C. had I realized　　 D. did I realize

46.　 The disc, digitally ______ in the studio, sounded fantastic at the party that night.

A. recorded　　 B. recording　　 C. to be recorded　　 D. having recorded

45.　 Don’t use words, expressions, or phrases ______ only to people with specific knowledge.

A. being known　　 B. having been known　 C. to be known　 D. known