1. The bill has been paid by Nancy.

2. A hamburger has been eaten.

3. The present has been opened.

4. The cats had been fed by Ann.

5. The book hasn't been read.

6. The letter hasn't been sent.

7. The thieves haven't been caught.

8. Our homework has been done. 

9. A email has been written for 2 hours by my friend.

10. Their work had been finished.

11. The English grammar has been explained by our teachers.

1. The bill has been paid by Nancy

2.A hamburger has been eaten by me

3. The present has been opened by me

4.The cats had been fed by Ann

5.The book hasn't been read by them

6.Letter hasn't been sent by yours

7.The thieves haven't been caught by them

8.Our homework have been done by us

9.An email has been written by my friend for two hours

10. Their work had been finished 

11.The English grammar has been explained by our teachers