Giúp mình bài này với ạ

Đáp án + Giải thích các bước giải:

 Ex2: Change the following sentences into the passive.

2. This car was bought 5 months ago.

Câu bị động: S là this car, câu gốc là thì QK => was

3. A letter was written to him last month.

Câu bị động: S là A letter, câu gốc là thì QK => was

4. I was told that our teacher was sick. 

Câu bị động: S là I, câu gốc là thì QK=> was

5. Mary was given this present an hour ago.

Nếu câu gốc S là They, Someone, Somebody,... thì có thể lược bỏ khi chuyển sang dạng bị động

6. A cake was made for Mary's birthday (by her).

7. His homework wasn't be done yesterday.

Câu bị động: S là His homework - N không đếm được, câu gốc là phủ định thì QKĐ => was

8. Tennis was played with my friend by me last Sunday.

9. This picture was drawn by herself.