31. ______ have you been to Shanghai?　 Only once.

　　 A. How often　 B. How long　 C. How many times　 D. How many time

30. We hope our world will become ______.

　　 A. beautifuller　 B. more much beautiful　 C. much beautiful D. much more beautiful

29. The children helped _____ apples on the farm.

　　 A. pick　 B. picked　 C. picking　　 D. to picking

28. My sister _____ home since she was seventeen.

　　 A. has been away　 B. has been away from　 C. has been from　 D. has left

27. In the exam, the _____ you are, the ____ mistakes you will make.

　　 A. careful, little　 B. more careful, less　 C. more careful, few D. more careful, fewer

26. Jim isn’t here. He _____ the farm ____ the farmers.

　　 A. went to, helped B. went to, to help C. has gone to, to help D. has been to, to help

25. Hurry up! The play _____ for ten minutes.

　　 A. has begun　 B. has been on　 C. began　 D. has been

24. Where is my pen? Where _____ I ______ it?

　　 A. did, leave　 B. did, forget　 C. do, leave　 D. will, forget

23. Look! There is so much rubbish on the ground.　 Let’s ______.

　　 A. pick it up　 B. pick up it　 C. pick them up　 D. pick up them

22. Now the air in our hometown is _____ than it was before, we must do something for that.　 A. much better　 B. more worse　 C. more better　 D. much worse