Viết lại câu:
1 .john cooked dinner and then cleaned the floor
–>john
2.she made a birthday cake.then her son came home.
–>by the time
3.peter prepared for the meal.then his mother got home.
–> by the time
4.i helped my young brother with his homework and then washed the clothes.
–>i
1, John had cooked dinner before he cleaned the floor
2, By the time her son came home, she had made a birthday party cake
3, By the time his mother got home, Peter had prepared for the meal
4, I had helped my young brother with his homework before I washed the clothes