Exercise 7:

1. to go → go

2. going → go

3. at → for

4. brush → brushes

5. takes → take

6. have → has

7. didn't → did

8. an → a

9. to → at

10. because → so

Execise 8:
1. You should take a rest and shouldn't carrry heavy things.

2. He shouldn't eat too much ice cream

3. You should go to the doctor's

4. You had better not play sports for a few days.

5. Does your son have a high fever ?

6. His father should not carry heavy things.

7. Nam should go to the dentist because he has a toothache

8. She had a bad cold so she didn't go to school.

9. She will take after her daughter to the doctor work.

10. Did you feel unwell and go home early yesterday ?

`Ex 7:`

1. to → bỏ "to"

2. going → go

3. at → for

4. brush → brushes

5. drink → drinks

6. have → has

7. Where → Why

8. an → a

9. to → at

10. because → so

`Ex 8:` 

1. You should take a rest and shouldn't carry heavy things

2. He shouldn't eat too much ice-cream

3. You should go to the doctor's

4. You had better not play sports for a few days

5. Does your son have a high fever?

6. His father should not carry heavy things

7. Nam should go to the dentist because he has a toothache 

8. She had a bad cold so she didn't go to school 

9. She will take after her daughter to the doctor's work.

10. Did you feel unwell and go home early yesterday?