过去完成时用于描述在过去某一时间或动作之前已经完成的动作或状态。以下是使用“work”的过去完成时的一些例句：
1. By the time I arrived, they had already worked for 3 hours.
2. The project was worked on by a team of experts.
3. I had finished my homework before supper.
4. The play had already started when we got to the theatre.
5. By the end of June they had treated over 10000 patients.
6. Had he gone home when you arrived？
7. To the time we left, they had completed the project.
希望这些例句能帮助你更好地理解和使用“work”的过去完成时。
