65. The students _____________(do) their homework.__________( not make) any noise!

64. Her mother____________(cook) at this time yesterday.

63. Mary said that she __________(visit) her aunt the next week.

62. The dog_________(lie) on the floor when I came in.

61. The desk must______(clean) once a day.

60. The stone bridge______________(build) in our hometown for ten years.

59. When I got to the station, the train____ already______(leave).

58. I didn't know what __________(happen) to China in a century.

57. She said that the car___________(use) the next week.

56. When______you______(see) him? I______(see) him last Sunday.