31.-I'm told that John had another car accident this morning.
-I believe not. He ______ so careless.
A. shouldn't have been B. wouldn't have been
C. couldn't have been D. mustn't have been
30.The Bunsen Burner is so named because it is thought ___ by Robert Bunsen.
A. to be invented B. having been invented
C. invented D. to have been invented
29.-Did the door-keeper let you in?
-No. _________ I tried to tell him I was your relative, he just didn't believe me.
A. Even if B. However C. No matter D. Whether
28. -_______ did you sleep last night?
- I sat up reading too late to fall asleep.
A. How long B. When C. How soon D. How
27.I have no idea _________ she gets on well with her classmates.
A. when B. how C. that D. which
26.Our TV sets sell well, but ten years ago no one could have imagined such a big share in the market. that they____.
A. were having B. had had C. were to have D. had
25.For weeks the street hasn't been cleaned by the cleaner, ___________ makes it very dirty.
A. who B. which C. that D. this
24.Unfortunately. when I dropped in. Professor Li ____, so we only had time for a few words.
A. just left B. has just left C. was just leaving D. had just left
23. In salad bars the waiter does not bring you salad. You have to __________ yourself, usually to as much as you want.
A. bring B. serve C. help D. supply
22. – How do you like ____ here so far, Mr. Cox?
- Well, I've really enjoyed meeting many nice people here and everything here is quite different.
A. it B. them
C. that D. this