They are studying hard in the library.(对 are studying hard提问)

问题描述:

They are studying hard in the library.(对 are studying hard提问)
_____ are they____ in the libray?

楼主你好,这句话的意思是他们正在图书馆努力学习.如果要对努力学习提问的话,就应该是问他们在图书馆做什么?就是: What are they doing in the library?