先行词是reason,但引导定语从句的词不用why的情况.

(1)在reason作先行词的定语从句中，若从句表原因，一般用why引导定语从句，why可以用for which替换。why还可省去。 The reason why (for which) he has resigned is poor health.他辞职的理由是健康状况不佳。 (2)当reason用作定语从句的宾语时，引导词用that/which,而且that/which可省去。 The reason (that/which) he gave for being l