1. Helen was found in the swimming pool.
2. The Olympic Games are held in Greece.
3. These competitions are held in Moscow.
4. Mary was met by Jack.
5. Jane was met by parents at the airport.
6. That book is read be Boris.
7. It was understood by us that we had to meet at dinner.
8 и 9 нельзя преобразовать в страдательный залог. если очень натянуть, то можно сказать
8. The vase was put on the table.
9. The bag was put near the desk.
10. The game was won by our team.
11. This competition was won by our athletes.
Grandpa and Grandma have got ten COWs 2) five CHICKENS 3) four GOATS