the reason why he doesnt come to school is not clear. 为啥有了reason 还要用why呢?

Do you know the reason why/for which he didn't come?这句话的意思? He wants to know the reason why,为何用why,reason是状He wants to know the reason why,为何用why,reason是状语吗,为什么 Do you think the reason ( ) he gave.is belDo you think the reason ( ) he gave.is believable?A.for which B.which.C.why.D.what He continued_____(explain) the reason why he was late 定语从句do you know the reason why he didn't come?我把why换成that可以吗?变成 do you know the reason that he didn't come Do you know the reason ( )he gave for being absent from school A which B why C when D what The reason why he was late was true . 改错:the reason why he is always late for class the reason that和the reason why the reason why与 the reason the reason why he doesnt come to school is not clear. 为啥有了reason 还要用why呢? 定语从句do you know the reason why he didn't come?为什么可以用why?从句后he是主语,didn't come是谓语,不是缺宾语吗?那怎么还可以用why I do not know the reason why he looks unhappy today.the reason后的why可不可以换成that,如果可以,他们有什么区别?如果不可以又为什么?要怎么区别the reason后面什么时候用why什么时候用that 麻烦清楚一点 the reason why he told me that he lost the money... The reason why he was late was that he was held up in the traffic jam. The reason why he was late was that he was held up in the traffic jam. 第一句：do yoi think the reason _which_ he gave is believeable.第二句：i don not believe the reason why/for which he was late for school.为什么第一句用which,第二句用Why或for which,the reason 在句中分别作什么成分?请分 the reason why 的用法