20. Đổi động từ...
1. broke
2. went
3. stool
4. went
5. opened
6. saw
7. was
8. ate
9. saw
10. was
11. drank
12. felt
13. fell
14. woke up
15. were
Ex.3: Chuyển sang...
1. (-) My mother wasn't born on $3^{rd}$ March
(?) When was your mother born?
2. (-) He wasn't a student last year.
(?) What was he last year?
3. (-) These exercises were not difficult
(?) How were these exercises?
