After the discussion,the student asked their teacher____next.

问题描述:

After the discussion,the student asked their teacher____next.
A.what to do B.where to do C.how to do D.which to do
Why?

A
what to do 做什么?这里what 做了do 的宾语,同时几个词合一起做了ask的宾语
where to do?哪里做?这时候do是有意义动词,且是及物动词,要有宾语,也就是要有干什么,有了干什么之后,就变成,在哪里做.比如it,就成了where to do it
how to do?怎样做?同上面一样,要有how to do it
D,which不能单独用,后面要跟内容!