why not do sth全句是 why shall we not do sth why not do sth?以前我记得是why don't you do sth 可今天我在教师用书中发现是why shall we not do sth 这该怎么讲?请赐教

why not do sth 还是doing sth 是why not do sth.还是why not doing sth. why not doing sth还是why not do sth还是why not to do sth 用why not do sth造句 why not do sth sb放哪? why not do sth ?的用法 why not to do sth对吗?waiting why do not do sth与why not do sth有什么区别? why not后面是doing sth还是 to do sth 是Why not to do sth还是Why not do sth? 那个语法是why not to do Sth还是why not do Sth why not do sthwhy not to do sthwhich is right why not do sth全句是 why shall we not do sth why not do sth?以前我记得是why don't you do sth 可今天我在教师用书中发现是why shall we not do sth 这该怎么讲?请赐教 why not doing sth和 why not do sth的区别 Why not do sth.=Why don't you do sth.=什么? why not do sth.=why don't you do sth.还等于什么 是why bot do sth.还是why not to do sth. Why don't do sth和 why not do sth有什么区别?