What are those?___They are books.(改为单数句）—————？————————。
问题描述：
What are those?___They are books.(改为单数句）
—————？————————。
答
what is this？ it is a book
答
what is this ? It is a book.
答
What is that? It's a book!
答
What's this？It's a book.
答
what is this?---This is a book.
答
what is this？-It is a book.
答
What is that?It is a book.