43.It was quite a long time＿＿＿ I made it out what had happened.

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

42.John must be in the chemistry lab,＿＿＿ ?

A.mustn’t he　　　　　　　　 B.needn’t he

C.isn’t he　　　　　　　　　 D.shouldn’t he

41.-- Helen must obey her parents.

-- Oh,she must,＿＿ ?

A.must she　　　　　　　　　 B.mustn’t she

C.shouldn’t she　　　　　　 D.should she

40.Information technology is taught in most schools,＿＿＿we have entered the information society.

A.so　　　　　 B.while　　　　　 C.still　　　　　 D.for

39.She is American,＿＿＿ she knows little about American history.

A.so　　　　　 B.yet　　　　　　 C.and　　　　　 D.therefore

38.It’s really very dangerous.One more step,＿＿＿the baby will fall into the well.

A.or　　　　　 B.so　　　　　　 C.but　　　　　 D.and

37.He made another wonderful discovery,＿＿＿ of great importance to science.

A.which I think is　　　　　　 B.which I think it is

C.which I think it　　　　　　 D.I think is

36.The Oscar is one of the film prizes ＿＿offered to any Chinese actor or actress so far.

A.which is not　　　　　　　　 B.that have not been

C.that has not　　　　　　　　 D.that has not been

35.She won the first prize in the speech contest and＿＿＿ surprised us.

A.which　　　　 B.it　　　　　　 C.as　　　　　 D.who

34.Everything depends on＿＿they will support you about it.

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