the children are playing games?(就划线部分提问）
问题描述：
the children are playing games?(就划线部分提问）
答
what are the children doing?(对playing games提问）
who are piaying games
答
我会告诉你没有线？。。
答
what are the children doing?(对playing games提问）
who are piaying games(对the children提问）