what is it it is a book 对 ? 还是it is the book对?

问题描述:

what is it it is a book 对 ? 还是it is the book对?
如题,我认为两个都对啊!

应该是it is a book.
不过有些时候还是要看具体情况的,如果这本书是已知的特指的,那这个时候就应该用it is the book.那要怎么改这个句子才能加the呢?