b1
1. can't, can
2 must
3. must
4. musn't
5. can't, could
6. can't
7. must
8. can
9. can't
10. must
11. can
12. can't
13. musn't
14. can
15. couldn't
16. musn't
17. musn't
18. must
19. ?
20. must
21. can;t
22. can, couldn't
23. must
24. can't
25. must
b2
1. Do you come tonight ?
2. does he eat rice everyday ?
3. i am working at the moment
4. does he come
5. he is playing
6. do you come
7. they do not come
8. he is not playing
9. do you play
10. they go
11. she does not go
12. arrive
13. eats
14. do you study
15. do they work
16. do not go
17. do not work
18. is she working
19. do not drink
20. is sleeping
