1. can't, can
2. must
3. must
4. mustn't
5. can't, could
6. can't
7. can't
8. can't
9. can't
10. must
11. can
12. can't
13. mustn't
14. can
15. couldn't
16. mustn't
17. mustn't
18. can't
19. couldn't
20. must
21. can't
22. can't, could
23. must
24. can't
25. must