11. A lot of books are read
12. Dinner is cooked every day
13. Milk is delivered in the morning
14. Flowers are bought for the flat
15. The cars are washed every week
16. A porter is wrote every Friday
17. The roads are fixed
18. New houses are built every year
19. Vegetables are sold in the market
20. The office is cleaned every day
*Không cần phải thêm "by somebody"
*HTĐ: S + am/ is/ are + PP + (by O)