This is 是什么句型?怎样变疑问句
问题描述：
This is 是什么句型?怎样变疑问句
答
这是一个陈述句.例句如下:
This is a pen.陈述句
Is this a pen?Yes,it is .No,it isn't.一般疑问句
What is this? it is a pen.特殊疑问句