51. --You look tired. Didn't you sleep well last night? 　--No, I _____until midnight last night.

　 A. hunted for　　 B. stayed up 　C. came about　 D. cared about

50.When I was a child, my teacher told me that the earth _____ round?

　 A. was　　　 B. had been　　 C. has been　　 D. is

49. Dave is _____ that we all like to play with him.

　 A. so a smart boy　 B. a such smart boy 　C. such a smart boy　 D. a so smart boy

48. I'm not into hiking. _____.

　 A. So is Ann　　 B. Ann isn't, too 　C. Neither is Ann　　 D. Nor isn't Ann　

47. The two boys were fighting each other, and it was hard for the old man to _____ them.

　 A. separate　　 B. keep　 C. divide　 D. cut

46. I was surfing the Internet _____ there was a knock on the door.

　 A. while　　 B. however　　 C. when　　 D. and

45. Your brother_____ you is very kind to me.

　 A. and　 B. or　　 C. as well as　 D. as well

44. -- Mum, it's time for me to go to school. 　-- Ok. _____ for cars when you cross the street.

　 A. Look after　　 B. Watch over 　C. Watch out　　 D. Pay attention

43. It's getting warmer and warmer, so the students of Class One are considering _____

　 the hill next weekend.

　 A. to climb　 B. climbing 　　C. climb　　 D. climbed

42. You will fail in the coming final examination you work hard at your lessons.

　 A. unless　 　B. if　 C. whether 　D. when