1a. He didn't send letter to his friend.

       Did he send letter to his friend?

b. The children don't wash their hands before meals.

Do the children wash their hands before meals?

c. The people weren't friendly.

Were the people friendly?

2.a. It takes the boy 3 hours a day to learn the lesson.

b. I spent half an hour cleaning the floor.

3. a. They returned to Hue after visiting Hanoi.

b. She always gives me the stamps from she recieved letters.

Chuẩn xác nhất nhé! Nhớ cho 5 sao, ý kiến và bình chọn hay nhất để được hỗ trợ tốt nhất nha! Chúc học tốt! 

1/ a)The letter was sent to his friend by him

b) Their hands are washed before meals by the children

c) The people were sociable

2/ a) It takes the boy 3 hours a day to learn the lesson

b) I spend half an hour cleaning the floor

3/ a) They returned to Hanoi after visiting Hue