Answer:
1. Can't
2. Should
3. mustn't
4. Might
5. shouldn't
6. don't have to
7. must
8. couldn't
9. can
10. shouldn't
11. won't
12. Can
13. can't
14. must
15. Can can't
16. can't
17. doesn't have to
18. may
19. Could or Can
20. Can
21. should
22. can't
Explanation:
1.b
2.a
3.b
4.c
5.a
6.c
7.b
8.c
9.can
10.shouldn’t
11.didn’t have to
12.can
13.can’t
14.must
15.couldn’t for both blanks.
16.can
17.shouldn’t
18.may
19.can
20.can
21.should
22.shouldn’t
