What is this?  变为What are these?
What is that? 变为What are those?
What is it?  变为What are they?
Who is he? 变为Who are they?
How much is it?  变为How much are they?
It is a pear. 变为They are pears. 
This is a pear.变为These are pears.
That is a pear.变为Those are pears.
五年级英语单数变复数的句子
I have an apple
I have two apple
一个苹果用an apple
两个苹果用two apples