34. Some researchers believe that there is no doubt ______ a cure for AIDS will be found.

　 A. which　　　　　　　 B. that　　　　　　　 C. what　　　　　　 D. whether

33. -- I've taken someone else's green sweater by mistake.

　 -- It ______ Harry's. He always wears green.

　 A. has to be　　　　　　 B. will be　　　　　 C. mustn't be　　　　 D. could be

32. The policeman's attention was suddenly caught by a small box which ______ placed under the Minister's car.

　 A. has been　　　　　　 B. was being　　　　 C. had been　　　　 D. would be

31. He hurried to the station only ______ that the train had left.

　 A. to find　　　　　　　 B. finding　　　　　 C. found　　　　　　 　D. to have found

30. The American Civil War lasted four years ______ the North won in the end.

　 A. after　　　　　　　　 B. before　　　　　　 C. when　　　　　　 D. then

29. I think he's just going to deal with this problem ______ day.

　 A. next　　　　　　　　 B. other　　　　　　　 C. following　　　　　 D. another

28. Years ago we didn't know this, but recent science ______ that people who don't sleep well soon get ill.

　 A. showed　　　　　　　 B. has shown　　　　 C. will show　　　　 D. is showing

27. John is very lazy. He falls ______ behind in his studies.

　 A. very　　　　　　　　　 B. far　　　　　　　　 C. more　　　　　　　 D. still

26. You'd better take something to read when you go to see the doctor ______ you have to wait.

　 A. even if　　　　　　　 B. as if　　　　　　　 C. in case　　　　　　 D. in order that

25. John is leaving for London tomorrow and I will ______ him ______ at the airport.

　 A. send ... away　　　　 B. leave ... off　　　 C. see ... off　　　　 D. show ... around