同义句转化 1.When his mother was ill,he had to take care of his sister at home.
When his mother was ill,he had to（ ）（ ）his sister at home.
2.A boy is eight years old.He can play chess very well.（ ）（ ）boy can play chess very well.
3.He didin‘t use to be strong.He （ ）（ ）（ ）be strong.
4.Kathy isn’t a little girl any longer.Kathy is（ ）（ ）a little girl.
5.I decided to buy a new computer.I （ ）（ ）（ ）to buy a new computer.