Chuyển thành câu bị động: Why did this boy break my window yesterday?

Chuyển thành câu bị động
1.      Why did this boy break my window yesterday?

2.      They have not known him well.

3.      Did you do your test perfectly?

4.      Why didn’t you learn this lesson?

5.      How long have they done their work?

6.      No one could help him.

7.      My father is painting our house.

8.      My brother uses a pencil to draw beautiful pictures.

9.      He has already finished his exercises.

10.     Hoi An attracts a lot of tourists.

11.     Farmer can milk cows twice a day.