题目内容：

could you tell me ( )? what are they doing that for, why they are doing for ,
why are they doing that, what they are doing that for 为什么选d

优质解答

因为是要带从句,所以what are they doing that fo 和 why are they doing that是错的,要用陈述语序.why提问原因,不能与for搭配,只能选what they are doing that for