why don't ,why not & why not do 答题的时候用在什么情况?

Why not do 和 Why don't do 什么区别 why don't you do=why not doing why don't和why not Why don't you+...why not +. why not 同义词是 why don't you 还是 why don't you do Why don't do sth和 why not do sth有什么区别? why not do sth.=why don't you do sth.还等于什么 Why not do sth.=Why don't you do sth.=什么? Why not,Why don't.有什么区别? why not 和why don't 有什么区别啊! Why not和 Why don't的区别 Why not 和Why don`t的区分