51. The volunteer devoted all her life to ___________ our environment. (improve)
52. In the United States, lunch __________ to students for free at school. (offer)
53. I found a wallet lying in the corner when I __________ the floor yesterday. (sweep)
54. It is said that the director ___________ another comedy in Shanxi at
present. (film)
55. Do you know which shop he went to __________ the snacks? (buy)
56. The woman looks excited because her favourite singer __________ on TV last night. (interview)
57. People were told that the plane __________ off until the rain stopped. (not take.)
58. The radio says that the rain __________ for half a day. What can we do? (last)
59. Must all the rules __________ to the players clearly before the game? (explain)
60. I’m surprised to find that the price of bread _________ by 15% recently. (rise)