Ответ:

1. "The Magic Flute" was written by Mozart

2. The flowers are being watered by a gardener

3. Our bags were checked by a friendly policeman

4. The evidence was being examined by Police officers

5. The documents were sent to the wrong address by them

6. excellent food is served by this restaurant

7. Very good cars is made in Japan by them

8. Arrangements are being made for the party by the students

9. English is spoken in most parts of the world by people

10. The two men were arrested after the robbery by them

11. The New Year's concert is heard every year by people