1 When did you receive a letter from Lan?
2 What does Minh usually do after getting up?
3 How often do you brush your teeth?
4 What time does Nga have an appointment this morning?
5 What time does she go to bed?
6 When did you begin to study El?
7 Where do they live?
9 Who did you go to disco with last night?
10 What is she worried about?
11.Does music make humans different from all other animals?
12.When do they do their homework ?
13.Who came to the party alone?
14.Which blouse do you like?
15. What is that?
16. How long did she talk to him?
17. What does he study at the university?
18. What is your telephone number?
19. What is your father?
20. How are you?