变为复数形式
问题描述：
变为复数形式
It's a knife
He is an English teacher
I'm a student
就换线部分提问
Thses are (Aaerican cars 划线)
The apples are (on the three 划线）
That boy is (Paul划线）
答
they are knives
they are english teachers
we are students
what are these
where are the apples
who is the boy