=>
9. The house is cleaned by my mother.
10. John's homework is done.
11. They suggest that advertisements on TV should be banned.
12. The door is shut (by me) if you like.
13. A horrible accident was seen by us.
14. The town was destroyed by an earthquake.
15. The letter wasn't typed by him last night.
16. I was picked up at my house.
Bị động HTĐ : S is/am/are (not) V3/ed (by O)
Bị động QKĐ : S was/were (not) V3/ed (by O)
Suggest that S should be V3/ed