过去完成时是英语中常用的一种时态，它用来表达过去某个时间点之前已经完成的动作或状态。下面是一些关于过去完成时的填空题及答案，供大家练习。
填空题
- By the time we arrived at the party, the guests __________. (已经离开)
- She was tired because she __________ for 10 hours. (已经 worked)
- He __________ his homework before he went to bed. (已经 finished)
- The train had left the station before we __________. (到达)
- They __________ the movie twice before they understood it. (已经 watched)
答案
- had already left
- had already worked
- had already finished
- arrived
- had already watched
以上是关于过去完成时填空题及答案的练习，希望大家能够掌握好这种时态的用法，提高英语水平。
