54. He said that it was so; he was mistaken, _____.

　　　 A. yet　　　　　　 B. besides　　　　　　　 C. while　　　　　　　　 D.　 though

53.This composition is all right; there is room for improvement, ____.

　　　 A. however　　　　　　 B. besides　　　　　　　 C. while　　　　　　　　 D. though

52. This task is very difficult; ______, time presses.

　　　 A. however　　　　　　 B. besides　　　　　　　　　　 C. while　　　　 D. although

51. You shouldn’t go out on such a dark night; _____ , it was raining so hard.

　　　 A. however　　　　　　 B. besides　　　　　　　 C. while　　　　 D. in fact

50. You shouldn’t to go to the football match; ____, it’s starting to snow.

　　　 A. although　　　　　 B. besides　　　 C. except　　　　 D. however

49. Five minutes earlier, and we ____ the last train.

　　　 A. caught　　　　　　　 B. could catch　　　　 C. could have caught　　　　　　 D. were able to catch

48. ____, so he didn’t go to school.

　　　 A. Mother being ill　　　　　　　　　　　　　　　　　　 B. His mother was ill　　　　　　

C. Because his mother was ill　　　　　　　　　　　　　　 D. Being ill

47. I’d like to borrow a copy of Sister Carrie. ____, but the book is out.

　　　 A. Excuse me　　　　　　　 B. Pardon　　　　　　　　　　 C. Sorry 　　　　　　　 D. I’m afraid

46. ____ your head, then you _____ a good idea.

　　　 A. Use; will have　　　　　 B. To use; had had　　　　 C. Using; have　　　　　　　 D. Used; had

45. I didn’t get the work done, ____.

　　　 A. I didn’t know who did it　　　　　　　　 B. nor do I know who did it

　　　 C. I neither knew who had it done　　　　 D. neither did I know who got it done