1. We usually lock the safe carefully.
The safe is usually locked carefully.
2. We keep the safe in the bedroom on the second floor.
The safe is kept in the bedroom on the second floor.
3. Yesterday the thieves stole everything in it.
Yesterday everything in it was stolen by the thieves.
4. We told the police about it.
The police were told about it.
5. The police checked everything in the house.
Everything in the house were checked by the police.
6. The police questioned everybody in the house.
Everybody in the house were questioned by the police.
7. The police surrounded the house.
The house was surrounded by the police.
8. The police did not think that they caught the thieves.
The police did not think that the thieves were caught by them.