41. It was _______ who helped Tom out when he was in trouble.

　　A. I B. me C. us D. ours

　　42. The leaves of many trees turn ______ in autumn.

　　A. to red D. red C. to be red D. into red

　　43.—Will you go to the museum tomorrow?

　　—Yes, I will go _______ it’s windy.

　　A. since B. as though C. if D. even though

　　44. Mary used to stay up until far into the night, ______?

　　A. didn’t she B. usedn’t she C. does she D. Both A& B.

　　45. It is very kind ______ you to supply us _______ so much information.

　　A. for…with B. for…in C. of…with D. of…in

　　46. Five minutes earlier, _______ we could have caught the last train.

　　A. of B. but C. and D. so

　　47. Many a boy and many a girl _______ it since then.

　　A. have seen B. has seen C. has been seeing D. had seen

　　48. I regretted _______ the days when I _______ hard at school.

　　A. wasting…must have worked B. having wasted…should have worked

　　C. to waste…could work D. to have wasted…would work