The reason ________ he is unhappy is ________ he has failed the exam．A.which; because B.for that; that C.why; that D.for; because

That was the reason ________ he told me yesterday. The reason why the emperor built the wall was ________(protect) China.求理由加翻译,要准确, the reason that和the reason why the reason why与 the reason the very reason是什么意思the very reason The reason ________ he is unhappy is ________ he has failed the exam．A.which; because B.for that; that C.why; that D.for; because 谁知道the reason what is the reason with the same reason the reason causing the problem is ...应该是the reason for 还是 the reason 后面接ing the reason for和the reason why的区别? the reason for 与 the reason why的区别 是the reason for还是the.reason.why the reason of 与the reason for的区别 explain the reason还是explain for the reason the reason why 和the reason that有区别吗 the reason why和 the reason that 的区别 the reason why和the reason that两者如何区分