1. have visited.
2. has read.
3. haven't begun.
4. met.
5. has been
6. haven't started.
7. did your father give up.
8. Did you wash.
9. called.
10. moved.
11. has been.
12. have gone.
13. spent.
14. has explained.
15. has taken.
16. delivered.
17. hasn't finished.
18. haven't seen.
19. heard.
20. haven't seen.
Cho mình xin lỗi. Chỗ câu 11 là have been