17. My mother cooks me a new dish.
=> A new dish is cooked by my mother
18. He always buys me a new bag every year
=> A new bag is bought every year for me by him
19. He hasn't taught our class unit 7 yet
=> Our class haven't been taught unit 7 by him yet.
20. The children are cooking their mother some soup
=> Some soup is being cooked by children for their mother.
CHÚC BẠN HỌC TỐT
