Chuyển các câu sau thành câu bị động
1. I have heard her sing this song several times.
2. People saw him steal your car.
3. The teacher is watching them work.
4. People saw her driving a car near the bridge.
5. Do they hear someone shout ?
6. She helps me do all these difficult exercises.
7. The terrorists made the hostages lie down.
8. He won’t let you do that silly thing again.