Ex 1.
4. wears
5. sleeps
6. doesn't tidy
7. helps
8. eat
9. doesn't understand
10. is dusting
11. goes
12. has
13. is smoking
14. are watching
15. are repairing
16. does
17. visits
18. is shining
19. blows
20. doesn't ride
 

Ảnh 2
1. is coming
2. is teaching
3. is studying
4. are singing
5. aren't surfing
6. is not wearing
7. are sitting
8. is going
9. is traveling
10. are playing
11. is flying
12. is mending
13. is doing
14. is snowing
15. is baking
16. is enjoying
17. is preparing
18. are breaking
19. are behaving
20. is planting

Ảnh 3
1. b) is working
vì có "now", nên chia tiếp diễn
2. a) goes
Có " On Saturdays", chia theo hiện tại đơn
3. a) catches
Chia theo hiện tại đơn
4. a) drinks
Có "often", chia theo hiện tại đơn
5. b) is having
Chia theo ht tiếp diễn vì có giờ
6. a) is finishing
"At 2,15 pm", nên chia theo ht tiếp diễn
7. a) are reading
Vì có "now", nên chia theo ht tiếp diễn