1. a new book has been published recently by them

2. our local museum has just been opened by the town counceil.

3. Their house has been painted by them.

4. The room has been cleaned by somebody.

5. The drees has been washed by somebody.

6. The dinner has just been cooked by somebody.

7. A new theatre has been opened in the city by them.

8. The letters have been posted by somebody.
как перевести эти предложения?и какое время используется?