52. Can't you see I'm busy __________? (cook)　　　　　　　　　　　　　 　

50. The boys _______ basketball on the playground are my classmates. (play)　　　　　　　　　　　　　　 51. I regretted answering like that, I was sorry __________ so. (do)　　 　

49. A new theatre __________ now. (build)　　　　　　　　　　　　　

48. I'm sorry to have kept you __________. (wait) 　　　　　　　　

47. John stopped ______a rest (have) because he ____ for three hours. (work)　　　　　　　　　　　

45. I'm sorry you've missed the last bus. It ____ ten minutes ago. (leave)　　　　　　　　　　　　　 46. Wei Fang is heard __________ English every morning. (read)　　　

44. __________ I finish my homework in class? (必须)No, you needn't.　　

43. There __________ a physics test next Monday. (be)　　　　　　　　　

42. Do you remember __________ the film last year? (see)　　　　　　　

41. The boy __________ by the door is my brother. (stand)