were not
has gone
has worked
has taken
has played
16. They ( not be ) ______didn't be____ at home yesterday.
17. He (go) ____has gone______ to Ha Long Bay for 2 weeks.
18. Mary ( work) ______has worked____ here since last night.
19. Nam ( take ) ____has taken______ the bus to school since last night.
20. He ( play ) ____has played______ volleyball for 10 years .
1. weren't
2/ has gone
3. has worked
19. has taken
20. has played