22题,不是有why not to do sth why don't you do sth

22题,不是有why not to do sth why don't you do sth 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 don't do sth和 why not do sth有什么区别? don't you do sth=why not do sth造句,词组造20句子, why not do sth why not +do sth why not doing sth还是why not do sth还是why not to do sth 英语造句急!why not do sthwhy don't you do sth why not to do sth对吗?waiting why don’t you （to）do sth 中的to用加不 why not do sth 等于why dont you do sth 为什么后面要加动词原形呢不是to do 呢 请