I.

1. was

2. was

3. were

4. were

5. wasn't

6. wasn't

7.  wasn't

8. weren't

9. wasn't

10. was/wasn't

11. was

12. were

13. were/were

14. was

15. was

II. 

1. went

2. played

3. ate

4. took

5. had

6. didn't buy

7. didn't talk

8. didn't come

9. didn't close

10. didn't return

11. didn't eat

12. didn't go

13. didn't take

14. didn't have

15. were

16. played

17. tried

18. talked

19. stoped

20. worn

10. 

Bài 1:

1,was 

2,was

3,were 

4,were 

5,wasn't

6,wasn't 

7,wasn't 

8,weren't

9,wasn't 

10,Was /wasn't

11,Was 

12,were 

13,Was /was 

14,was 

15,was 

Bài 2:

1,went 

2,played 

3,ate 

4,took 

5,had 

6,Didn't... buy 

7,didn't talk

8,Didn't... come 

9,Didn't ...close 

10,didn't return 

11,didn't eat 

12,didn't go 

13,didn't take 

14,didn't have

15,Were Lan and Hoa at your school two years ago? 

16,did... play 

17,did... try

18,talked 

19,did they stop

20,did the student wear