句型转换 Are these your pencil-boxes?(改为单数形式） ___ ___ your___?

句型转换 Are these your pencil-boxes?(改为单数形式） ___ ___ your___?
We are in Class Three、Grade one .（对Class Three、Grade one进行提问）
___ ___are you in?
That is'n an old book.(改为复数形式）
__ __old____
We can see it.(改为否定句）
We __ __it.
We are in the same class(改为一般问句）
__ __in the same class?
将下列句子改为复数
This is my box.
That is your clock.
It is an apple.
He's a teacher.
Is that an orange?