#语法求助#centralization also refers to the extent to which people have to refer decisions upwards to their superiors. 这个句子我能理解，我就是理解不了这里to which是干什么用的？如果这个to which一直到后面是介宾短语做后置定语，那which在短语中逻辑上应该放在那个位置？或者to which当做状语，但是又该怎样里to 和which做什么成分？