keep out,keep off,与keep on的区别

keep out 阻止进入
keep off 让开；不接近
keep on 继续,坚持下去
either ['aiðə,'i:-] adj.两者之中任一的；两者之中每一的
prep.任何一个
conj.或者
adv.也（用于否定句或否定词组后）；[口]根本
Come either today or tomorrow.
你今天来或是明天来.
Either come in or go out.
要么就进来,要么就出去.
I want to visit either Paris or London.
我想去巴黎或者伦敦游览一下.