what's under the chair 回答是用什么?

what's under the chair 回答是用什么?
what's under the chair 回答是用什么?

what's under the chair 回答是用什么?
用There be句型
即：
What's under the chair
什么在椅子下?
There is a ball/doll/toy.under the chair
椅子下有一只球/娃娃/玩具……

它问的是“什么”，那你可以直接用名词回答。