Question

高分悬赏！高考英语单选一道关于定语从句与表语从句？？？

Evidence has been found through years of study___ children's early sleeping problems are likely to continue when they grow up.
A why
B that
我知道选B
1)如果选用why，why及空后的句子看成一个定语从句修饰evidence为什么不可以？
2)同位语从句是不是只是用来解释说明内容的

Answer 1

语法方面不讲，太抽象。

逻辑角度： Sleeping problem 是一个现象， Evidence 并不一定是这个现象的原因，同理也可以证明这个现象存在的证据，所以why引导的话将evidence限制在因果关系里面，逻辑荒谬。

而that引导并没有明确指出Evidence 和problem的关系，只是把study又解释了一遍，逻辑关系上是合理的，所以that无误。

Answer 2

Evidence （has been found through years of study）___ children's early sleeping problems are likely to continue when they grow up.
将括号里先不看，why引导的定语从句，why必须做成分，即状语，而且他的先行词常为reason.这句显然为同位语从句，因为句子不缺成分，用来解释说明Evidence

Answer 3

why定语从句的先行词必需是reason.
如 the reason why he didn't attend the meeting is that he was ill.
这个同位语从句是来解释说明前面名词evidence的内容的。

Answer 4

因为连接词“why”要跟在先行词后，若是定从原句应是“Evidence why children's early sleeping problems are likely tocintinue when they grow up has been found through years of study." 而同从that可以与它修饰的词语中间隔着词。

Answer 5

按你所说，why后面的内容修饰evidence的话原句应该改成：
Evidence why ... has been found through years of study.

原题中无论填什么词句子肯定是修饰study的，why是说不通的