有这么一道题，主要考查填that还是why：
Maybe this is also the cause ( ) she has become fatter these days.
从句相对完整，是要选that不做成分还是选why做从句状语，比较容易混淆（不像定语从句中缺个主语或宾语，肯定就选关系代词那么简单）。
如果填that，那就算是名词性从句中的同位语从句，cause与that she has become fatter these days是等价的，变胖是就是原因（比如变胖导致血压升高），即the cause is that she has become fatter；
如果填why，那就是why引导的定语从句，变胖是结果。显然这句话说的是“这可能也是她变胖的原因”，变胖是结果（比如吃饭不规律导致变胖），简化一下就是This is also why she has become fatter these days，即the cause explains why she has become fatter。
类似的题目还有The cause ( ) he failed the driving test is what I thought before.驾考失败是个结果，所以还是填why，不是that。
cause的意思与reason相仿，reason后接同
Maybe this is also the cause ( ) she has become fatter these days.
从句相对完整，是要选that不做成分还是选why做从句状语，比较容易混淆（不像定语从句中缺个主语或宾语，肯定就选关系代词那么简单）。
如果填that，那就算是名词性从句中的同位语从句，cause与that she has become fatter these days是等价的，变胖是就是原因（比如变胖导致血压升高），即the cause is that she has become fatter；
如果填why，那就是why引导的定语从句，变胖是结果。显然这句话说的是“这可能也是她变胖的原因”，变胖是结果（比如吃饭不规律导致变胖），简化一下就是This is also why she has become fatter these days，即the cause explains why she has become fatter。
类似的题目还有The cause ( ) he failed the driving test is what I thought before.驾考失败是个结果，所以还是填why，不是that。
cause的意思与reason相仿，reason后接同