Решение:
- The new house will be surrounded by garden.
- The book has been written by a group of authors.
- The sky is covered with clouds.
- I can open the door of my house with the key.
- The cat was killed by the car.
- The man was killed with the gun.
- The flat is heated by the central heating.
- He went to Sochi with his parents.
Ответ: 1. by 2. by 3. with 4. with 5. by 6. with 7. by 8. with