Results from the US National Heart,

来源：百度知道 编辑：UC知道 时间：2024/06/26 00:44:59
Results from the US National Heart, Lung and Blood Institute's study found that the odds of a child being obese increase about 14% for every five extra years of their mother's age,though why this should be so is not entirely clear.
最后从why开始怎么理解呢,so 在这里什么意思呢?有相关例句最好了,谢谢~~

why引导原因状语从句，这个很常见。如：I still don't know why he has cheated on her.我现在还不知道为什么他要背叛她。
so代替前面（the odds of a child being obese increase about 14% for every five extra years of their mother's age）整句，就是这个现象.

为什么会如此的原因却并不十分清楚。
so在这里是指它上面所说的那个现象。