Question

The reason__she gave up teaching was her serious illness

我认为这道题即可看成定语从句也可看成同位语从句，大家都来议一议。

Answer 1

定语从句，她放弃教书的理由而同位语是解释说明这个理由的内容的，the reason= that 从句比较： the reason that he was ill made him fail the exam.这句话中the reason 不是说他生病的理由，而是说他生病就是原因。他考试不及格的原因是他生病了。这就叫同位语。再看一句：the reason why he was ill is that he was caught in the rain.这就是定语，他生病的理由就是淋雨了。the reason 和that 从句根本就不是一个意思。

Answer 2

The reason_why_she gave up teaching was her serious illness同位语，说明原因。

Answer 3

填that,是定语从句

Answer 4

why 定语从句

Answer 5

why同位语