1. Minh brushes his teeth (twice a day.)

->How often does Minh brush his teeth?

2. Simon is in a lot of pain now (because he has a toothache.)

->Why is Simon in a lot of pain now?

3. I felt (sick) after eating that food.

->How did you feel after eating that food?

4. Nga went to see the dentist (last week.)

->When did Nga go to see the dentist?

5. (Dr Lai) will check your teeth.

->Who will check your teeth?

6. It took Dr Phong (10 minutes) to fill Van’s tooth.

->How long did it take Dr Phong to fill Van's tooth?

7. My brother is going to (the hospital.)

->Where is your brother going to?

8. Mr. Cuong (did morning exercises) at 5.30 yesterday.

->What did Mr Cuong do at 5.30 yesterday?

9.Hoa received (her aunt’s) letter five days ago.

->Whose letter did Hoa receive five days ago?

10. There are (twelve) students in Lien’s class having toothache.

->How many students are there in Lien's class having toothache?