They like playing football.就画线部分提问 -------------------
问题描述：
They like playing football.就画线部分提问 -------------------
答
划线playing football
What do they like doing?
翻译：
他们喜欢做什么？
答
What do they like?
答
哪里有线?
如果是They,提问是Who like playing football?
如果是playing football,提问是What do they like?或者What sport do they like?
如果是football,提问是What do they like playing?
答
Who like playing football?