`3.` She was heard singing loudly.

`-` Bị động: QKĐ: S + was/were + V3/ed

`4.`

`=>` She let her books be borrowed by her sister.

`=>` Her sister was allowed to borrow her books.

`-` Chủ động: S + let + sb + V

`->` Bị động:

`+` S + let + sth + be + V3/ed + (by O)

`+` S + tobe + allowed + to V

`5.` The players are made to practice hard by the coach every day.

`-` Chủ động: S + make + sb + V

`->` Bị động: S + tobe + made + to V

`6.` We are allowed to leave early by our boss.

`-` Tương tự câu 4

`7.` I was made to cry by this film.

`-` Tương tự câu 5

3. Her singing loudly was heard by us.

4. Her books were let to be borrowed by her sister.

5. The players are made to practice hard everyday by the coach.

6. We were let to leave early by uor boss.

7. I was made to cry by this film.