理由行的英文

reason理由； no reason 没有理由

reasoncauseexcuse （借口）

reason原因excuse借口

reason: [ ri:zn ] n. 理由,原因,理智,理性 v. 说服,推论,下判断 [ 名词reasoner ] [ 过去式reasoned 过去分词reasoned 现在分词reasoning 第三人称单数reasons ] 例句与用法 1. She can reason very clearly. 她能很清晰地思考。 2. Copernicus reasoned that the earth revolved around the sun. 哥白尼论证了地球绕着太阳转。 3. We have reason to believe that he was murdered. 我们有理由相信他是被谋杀的。 4. The detective tried to reason out how the thief had escaped. 这个侦探反复琢磨想弄明白那个窃贼是怎样逃跑的。 5. He was excused by reason of his age. 他因为年龄的关系而得到宽恕。 6. It stands to reason that nobody will work without pay. 做工作不能白做，这是明摆著的事。

reason 是最常用的，但是要看你的具体用处。发一句话来也许可以给你一个更合适的答案。