(1)Why not...? Why not...?是why don’t you ...?的缩略结构。Why not后接动词原形,表示建议或请求。例如: Why not have a try=Why don’t you have a try?为什么不试一试呢? Why not go there by ship?(=Why don’t you go there by ship?)为什么不坐船去那儿呢? (2)What about和How...