Behaviorism looks at the human entity, at the person as basically a collection of behaviors as a box, like a billiard ball knocked around by reinforcements, by punishment, by reward.

行为主义认为人的主体性，认为人是一个行为集合，就像一只被击打而四处滚动的台球，被增强，奖惩驱动。

哈佛公开课 - 幸福课课程节选

You use the "who" questions to ask about subjects, to ask who the subject is of the certain action or anything really.

当你要询问主体，即某一行为或事物的主体时，你可以用“who”问句。

Who 课堂 - SpeakingMax英语口语达人