Question

一道选择题

4. The reason the little actress has been such a success is she is both clever and hard-working.
A. why, why B. why, that C. that, because D. for, because

答案是B，那为什么C不可以呢？

Answer 1

4. The reason ______ the little actress has been such a success is ______ she is both clever and hard-working.
A. why, why B. why, that C. that, because D. for, because
答案是B，那为什么C不可以呢？
虽然你漏掉了两个空，这对我们经常做这类题目的人而言，不是问题。
这题的记法就是：the reason why ... is that ...
why 从句是个定语从句，从句中， the little actress has been such a success 不缺主语也不缺宾语，而是缺个状语，解释“因为什么”的，而关系副词why=for which =for the reason, 因为这个原因
这句话想表达的是：这小演员成功的原因是什么。原因是什么呢，只要回答原因是什么就行了，也就下面用that来陈述一个事实即可。所以这个表语从句（属名词性从句）要用that来引导。
但是由于在汉语口语中，这么说的人很多，很顺口：她成功的原因是因为。。。，而许多中学老师，尤其是中国的老师问认为the reason .... is because .....是一不好的英语，所以这个题目就特别受老师门的欢迎，乐些不疲，以考倒学生为乐。英英Longman词典上说到：Somep people think a sentene such as "The reaso for my absence was beause I was ill" is bad English. It maybe better to say: The reason for my absence was that I was ill. 后一空不用because并不因为它是连词，不能引导名词性从句，其实它是可以引导名词性从句的，我们常可见到：That's because ...这样的句子 （那是因为。。。）。
当然可能还要指出，the reason 后不跟同位语从句，用that以为是同位语从句也是很牵强的。由于这两个原因，所以这题答案，当然是最佳案，无疑只能是B了。
顺便纠正楼上的一个错误，这个引导表语从句的that在词性上就是连词。

Answer 2

第一个空填why是因为这是一个定语从句。why修饰reason。如果你填that，那就是一个同位语从句了。但是后面这句话并不是reason的内容，而是reason的问题。
第二个空填that是因为is后面是一个表语从句需要用that引导。because是连词，这里不需要连词。这么说能懂么