介绍:
Unit20 过去完成时
1. She was very excited. She'd never flown before.
2. I had left the exmamination room before 11 o'clock.
3. By nine o'clock we'd already got everything ready.
4.By the time I got home, she had already gone to bed.
5. When I got the cinema, the film had already begun.
6. I had never seen such a wonderful match before that day.
7. She had taught here for ten years before she went abroad.
8. By the middle of last month I had lived in California for five years.
