40. The reason for _______ he failed in the exam was that he was too careless.

A. which 　　B. why 　　　　　　C. that 　　　D. it

39.What caused the accident and who was responsible for it_____a mystery to us.　　　

　　　　 A.remains　　 B.remain　　 C.is　　 D.look like

38.The cattle_____still grazing in the fields.

　　　　 A.was　　 B.keeps　　 C.were　　 D.won’t

37.One and a half bananas____eaten by the little boy.

　　　　 A.were　　 B.was　　 C.have been　　 D.was to

36.The rest of the lecture_____interesting.

　　　　 A.is　　 B.are　　 D.maybe　　 D.sound

35.－Must I take a taxi?

　　　 －No,you_____.You can walk from here.

　　　　 A.don’t 　　B.must not　　 C.don’t have to　　 D.had better not to

34.－Does Tom want to go to the film?

　 －Yes,but he says_____tonight.

　　　 A.he’d not rather go　　 B.he’ll rather not go

　　　 C.he won’t rather go　　 D.he’d rather not go

33.The flower is dead.I_____it more water.

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

32. He_____there now,but I am not sure.

　　　 A.maybe　　 B.may be　　 C.may have been　　 D.might have been

31.－Why didn’t you answer when I called you?

　 －I_____but you didn’t hear me.

　　　 A.had to　　 B.couldn’t　　 C.didn’t answer　　 D.did