if you don't know,who knows?这句话为什么不用“主将从现”?if引导的条件状语从句难道不是必须主将从现么?

If You Don T Know 歌词 you never know if you don't try If you don't know what you want是什么句型? IF YOU DON‘T KNOW HOW TO SPEAK IN ENGLISN； You don't know even if I vanish from your Hao can i know ,if you don't say If you don't know the way,_______please咋填 “if you don't want others to know about it ,don't do it. It doesn't matter if you don't know him well.if引导的是什么从句 “i don't know you know i don't know .If you don't know where are you going,any road will get you to there!.. what you don't know ,you don't know If You Don'T,Don'T 歌词 Don't You Know 歌词 you don't even know you don't know 中文 You don't know me You don't know nothing