20.1
2. Yes, I started it last week,
3. Yes, they arrived at 5 o'clock.
4. Yes, she went away of Friday.
5. Yes, I wore it yesterday.
20.2
3. I finished my work at 2 o'clock.
4. OK
5. What time did you finish your work?
6. OK
7. Steve's grandmother died two years ago.
8. Where were you last night?
20.3
3. played
4. did you go
5. Have you ever met
6. wasn't
7. has visited
8. switched
9. lived
10. haven't been