what is this 回答 与what is that 回答

what is this 回答 与what is that 回答
what is this 回答 与what is that 回答

what is this 回答 与what is that 回答
我告诉你吧.绝对不能用this 和that来回答.为了避免重复,应该把this和that改为it.即：It is a/an +名词（单数）.It is 可以缩略成It’s.
如：What is this?It’s a book.
又如：What is that?It’s a pen.
跟它类似的还有What are these?What are those?答语都用They're 不能用These are 和 Those are.

this is ...
that is ...

what is this 就回答 this is ___. 举例，what is this? this is a pen.
what is that 就回答 that is ___. 举例, what is that? that is a car.

what is this 这是什么
this is ... 这是..
what is that 那是什么
that is... 那是...

This is.../It is...
That is.../It is...