What is on the desk?是用It is a book回答,还是There is a book

There's a book.
小学英语中有一个重点练习项目
---What's +在某地?
----There be .
理解请赞同!
There's a book
potatoes [pəˈteitəuz]
apples [ˈæplz]
vegetables [ˈvedʒitəblz]
drinks [driŋks]那翻译呢potatoes [pəˈteitəuz]土豆apples [ˈæplz]苹果vegetables [ˈvedʒitəblz] 蔬菜drinks [driŋks]饮料不是这个是There is a bookWhat is on the desk？桌子上有什么？There is a book （桌子上） 有一本书。