夏天嘴唇脱皮是为什么?why?why?I will thank you very much .thanks

夏天嘴唇脱皮是为什么?why?why?I will thank you very much .thanks 为什么我必须去这个的句子翻译是 why must I go?而不是why I must go? 为什么一个是why is.一个是why are. 我为什么写 | Why I Write I dont know why he was late.这个句子里为什么用why不用that?我打错了　是Idont know the reason why he was late why are you know和why do you know的区别.还有:为什么我不知道用英文怎么说。是Why didn't i know吗 The reason why I come here is very clear.reason是come here的宾语吗?为什么用why? why 后加人称的什么格是why me 还是 why I ＷＨＹ? why? WHY? WHY? why why? why why why why