55. 昨天下午你看上去精疲力尽，发生了什么事？

You 　　　　　　　　　　yesterday afternoon. What 　　　　　　　　　　you.?

54. 当警察到达时，小偷已经跑掉了。

When the police 　　　　　, the thief 　　　　　already 　　　　　away.

53. 他告诉我们他从未去过巴黎。

He told us that he 　　　　　　　　　　　　　　　　　　　　Paris.

﹡﹡51. 当我到达火车站时，火车已经开走10分钟了。

When I got to the station, the train 　　　　　　　　　　　　　　　ten minutes.

52. 我到家后才意识到把手机落在出租车里了。

When I got home, I 　　　　　that I 　　　　　　　　　　my mobile phone in the taxi.

50. John met his best friend yesterday. They 　　　　　　each other since they graduated.

49. 　　　　　　, he missed the latest bus.

48. By the time I got to school, I realized I 　　　　　　my homework at home.

47. I didn’t see you 　　　　　　at the meeting. Where were you then?

45. The meeting 　　　　　　for five minutes when I got to the meeting room.

﹡﹡46. By the end of last year these books 　　　　　　in the library for fifty years.

44. They 　　　　　　letters to each other before they met.