21. In one year’s time, she________for this company for 15 years.A. will be working          B. will have been working

                                           C. will work                                                         D. has worked

22. His health has improved a lot since he________doing exercises regularly.

                                           A. starts                         B. started                       C. has started     D. had started

23. She hurt herself while she________hide-and-seek with her friends.

                                           A. is playing                  B. had played                C. played           D. was playing

24. .What________at 9 o’clock last night? I phoned you but couldn’t get through to you.

                                           A. did you do                B. were you doing         C. would you do            D. had you done

25. It is raining heavily with rolls of thunder. We________such a terrible thunderstorm.

                                           A. would never see        B. had never seen          C. have never seen        D. never see

26. I _______ my old teacher last week.                 A. visited                       B. visit   C. am visiting   D. have visited

27. My brother usually ________me for help when he has any difficulties with his homework.

                                           A. ask                            B. asks                           C. asked            D. has asked

28. I ______ all of my homework last night.           A. finishB. will finish    C. have finished            D. finished

29. Lan________ learning English a few years ago.                                      A. startsB. will start       C. started         D. is starting

30. Only after she________from a severe illness did she realize the importance of good health.

                                           A. would recover           B. has recoveredC. had recovered                       D. was recovering