5. The English grammar has been explained
6. The accident was caused in this city
7. His parents will be visited by him next month
8. The cecretary wasn't phoned
9. Was this beautiful dressed by Mary ?
10. These old picture won't be hung in the living room
11. This factory was not built by the German during the Second World War
12. This house and these cars are going to be painted by the Greens for Christmas Day
13. The cats have been fed by Ann before she went to the cinema
14. The pollution problems have been discussed since last week
*Nếu chủ ngữ không là ngôi ba số ít hay DT riêng thì không cần thêm by
