几道英语定语从句的问题1.The reason____she gave up teaching was her seri

1.D 她放弃教学的原因是她的重病.(B 也可以,）
我们把它还原成：She gave up teaching because the reason.(可见这里的reason是原因,用why)
2.B 他被撤职的原因是不难解释的.
我们可以把它还原成：He was dismissed for the reason.(也可以还原成：He was dissmissed because the reason.所以这里也可以用where ),
3.B 她和我们玩的这一天决不会被忘记.
我们可以把它还原成：She played with us on the day.( 看见了吗?我们可以在the day 的前面加上on,证明这里的the day是时间,用when引导,也可以用on which)

1、B、D
定语从句里，若先行词是reason，用介词for+关系代词 which或直接用关系副词why
翻译：她放弃教书的原因是由于她的疾病。
2、B
同上
翻译：他为什么被解雇的原因很难解释。
3、B
定语从句，先行词day在从句里对应的是时间状语，所以用关系副词when做从距离的时间状语，指代之前的day
她跟我们一起玩的日子...

第一题选b，d。she gave up teaching for the reason
第二题选b。he was dimissed for the reason
第三题选b。she played with us on that day

我是英语专业的，个人的语法方面感觉还是很好的。也简单查了一下。
1。D
因为用that的时候..The reason_that_she gave up teaching was her serious illness,这样的语句一看就知道是同位语从句..当句子是同位语从句时..可以省去_that_she gave up teaching 剩下The reason was her ...

1、B.for which the reason for........... "which she gave up teaching"定语从句修饰reason
2、A.that that引导的定语从句补充说明reason
3、D./ 凭语感
以上仅个人见解，希望有助于你