1. B. have

2. B. is writing

3. A has been studying

4. B. of

5. C. is

6. C famous

7. B. off

8. B of

9. B. had been studying

10. C. had lived

11. A. Mary said she was speaking with her mom.

12. A suits

15. C met

14. B. was watching

15.  Can

16. A. will turn

17. A. off

18. C about

19. A will get

20. B. should