Odpowiedź:
1. ... by our dog.
3. ... by them.
4. The fire alarm was tested by the electricians.
5. A new car was bought by my friend.
6. The bathroom was cleaned by John.
7. The blue jeans were invented by Levi Strauss.
8. A new kind of washing powder was developed by them.
9. The mountains were covered by snow.
Wyjaśnienie:
