Відповідь: 11. Is the timer settled by Stephan?

12. Three songs are sung by the artist.

13. The umbrellas are taken by Mr. Brown.

15.  A good job is done by policeman

16. Are my keys found by my friends?

17. A book is written by the scientist.

Пояснення: не уверенна, но надеюсь что правильно:))