53. Sorry, sir, I __________ (忘记) my English book at home

52. If you take more ______(锻炼), you will be much healthier than before.

51.It’s not right to____ (争吵)with your classmates.

20.----_______should I take this medicine, doctor?

　 ---- Three times a day.　

A. How often　　　 B. How soon　　 C. How long　　　　 D. How much

19. Nothing could stop the big ship ______ down.

A. to go　　　　　　　　 B. from going　　　 C. went　　　　　　　　 　 D. goes

18. Don’t get on or off the bus ______ it stops.

A. when　　　　 　　 B. if　　　　　　　　　 C. as soon as　　　　 　 D. until

17. The sick woman is 　　　weak 　　　　look after herself.

A. too; to　　　　　　 　　 B. so; that　 　　 C. very; to　　　　　 　 D. so; to

16. ----Would you please tell me how to get to the museum?

　 ----Yes. Go along the street. It’s on the left of the hospital. You can’t___ it.

A. find　　　　　　 B. miss　　　　 C. forget　　　　　 D. pass

15. ----We are free this afternoon. Let’s go to play computer games.

　 ---Well. I think I’d better watch an English program____.

A. too　　　　　　 B. either　　　　 C. then　　　　　　 D. instead