Odpowiedź:
1. ...by someone.
2. ...have been drunk by me.
4. This house will be bought by someone.
5. This work will be finished by her.
6. This question will be thoughtful by me tomorrow.
7. My house is looked after by my mother.
8. Very interesting books have been written by him.
9. Those letters already have been sent by me.
10. This dog have been found by someone yesterday.
11. The dictionary is always used by me.