把下面的复数句.改为单数句 ,单数句改为复数句 。 1.There are many sheep in the hills. 2.This is a box and that is a knife. 3.He is a baby. 4.They have many birthday presents.
1.There are many sheep in the hills. There is a sheep in the hills 2.This is a box and that is a knife. These are boxes and those are knives 3.He is a baby. They are babies 4.They have many birthday presents. He has a birthday present