31. --- Professor Brown, I enjoyed your lecture at HK University last year.

　 --- Thanks. But it ______ over two years ago, if I can remember rightly.

　 A. must have been　 B. can be　 　　　　C. may be　　　　　 D. might be

30. The theory which people have been against for years ______ true.

　 A. is proved　　　 B. proves　　　　　 C. is proved to be　　 D. is proving

29. We ______ there when it ______ to rain.

　 A. would get; began　　　　　　　　　 B. were getting; would begin

C. were about to get; began　　　　　　 D. had got; had begun

28. He came from Russia, ______ I detected from his strong Russian accent.

　 A. that　　　　　 B. what　　　　　　 C. as　　　　　　　 D. where

27. ______ being treated, it would produce a harmful chemical that would kill the patient.

　 A. Unless　　　　 B. If　　　　　　　 C. As　　　　　　　 D. Without

26. It would be unwise to ______ too much significance ______ these opinion differences.

　 A. attach; to　　　 B. refer; to　　　　 C. apply; to　　　　　 D. attend; to

25. In David Brown’s eyes, the way I had thought ______ different kinds of fruit into groups was a great success.

　 A. to put　　　　　 B. of putting　　　　 C. of; to putting　　　 D. of; of putting

24. For holidays, many people visit the Great Barrier Reef ______ the northeast coast of Australia.

　 A. in　　　　　　 B. on　　　　　　 C. within　　　　　　 D. off

23. As a reward for Aditi’s efforts, the boss insisted ______ a raise though she’s been in this department for less than two seasons.

　 A. on her giving　　 B. to give her　　　 C. she be given　　　 D. that she was given

22. Rachel Grey said she would come to help us; she didn’t, ______ .

　 A. yet　　　　　　 B. too　　　　　　 C . either　　　　　　 D. though