what is this和what is that的回答与区别 what are they和what are these

What is this有“这是什么?”的意思,What is that有“那是什么?”的意思,它们的区别在于前用来提问近距离的东西,后者是用来提问远距离的东西,它们的回答都可以用“It's .” What are they是他们(它们)是什么(谁)的意思,可于问人和物.What are these是这些是什么的意思,也是用来问近距离的东西,是“What is this”的复数形式 What are those是那是什么的意思,也是用来问远距离的东西,是“What is that”的复数形式

this is a pen
that is a dog
they are my friends
these/those are books