1. Read the example of the past perfect. Then look at the timeline and answer the question...

A. past perfect: had + past participle

Cách làm:
- Khi tôi đến nhà, thì phòng của tôi đã được dọn dẹp.

Câu trả lời:
- By the time I got home, somebody had already tidied my room.
- When I arrived home, my room had already been tidied by somebody.
- Upon my arrival, it was evident that someone had already tidied my room.