the two girls are reading under a tree?变为一般疑问句 are the two girls reading under a tree为什么reading 不可以用doing

问题描述:

the two girls are reading under a tree?
变为一般疑问句 are the two girls reading under a tree为什么reading 不可以用doing

原题是reading,变为一般疑问句不变啊
reading意思是在看书
doing的话,意思没有表达出来,在树下做什么呢...