1 Sam's car had been fixed by 6 o'clock.

2 My room had been cleaned before my mother came home.

3 A delicious cake had been baked by my granny before my friends came.

4. The flowers had been watered by 2 o'clock.

5. The letter had been posted before the headmaster came.

6. After the book had been read my mother let me go for a walk.

Ответ:

1. The homework had been prepared by 6 o'clock yesterday

2. The cake had been eaten by us

3. The T-shirt had been bought when I discovered I had no money left

4. The sweets had been eaten before mom prepared the soup.

5. Alice had been asked to babysit her neighbors’ son

6. This actor had been nominated for an Oscar.