why not +doing还是do

why not +doing还是do why not 后跟do 还是doing? why not do sth 还是doing sth Why not 后面+doing 还是to do? why not to do 还是why not doing 是why not do sth.还是why not doing sth. why not to do还是why not doing why not doing sth还是why not do sth还是why not to do sth why not后加do还是doing还是to do? why not后面是doing sth还是 to do sth why not +什么 doing?do? why not 后面加do还是to do还是doing?为什么?能不能具体点? why not do还是why not doing?老师上课讲的是why not doing,可是我做课外题时答案是why not do,谁知道到底是什么啊 why don't you do=why not doing 2/7这类分数用英语怎么说Why not+ do 还是 doing Why not _____a party this week?（后加have原形、to do形式、还是doing形式? why not do还是why not to do why not sb +do还是to do