先行词是reason的定语从句中why，that，这种的引导词可省去么？请举例回答，谢谢！

也要分情况的，主要是看that 在句中所起的作用而定。 不可省略的情况如，The reason why was late for school is that he didn't sleep well last night. 这句中 reason 后面的 why 引导原因性质的定义从句， 而that 紧跟在is 后面，作为表语从句，that 就不能省略。 而向 the reasons that he gave just now can not be trusted at all. 这句中，th