2. How often do the teacher and students do the experiments ?
=> They do experiments every Thursday.
3. What are the boys often do after school?
=> They often play football.
4. What time do these old people usually have a walk ?
=> They have a walk at 6 a.m.
5. What time does David often listen to music?
=> He often listens to music at 9 p.m.
Dấu hiệu thì : Hiện tại đơn
* Công thức :
( + ) S + V( s,es)
( - ) S + don't/doesn't + V
( ? ) Do/Does + S + V?