下面这个句子: ...,and hearings are held in which groups battle through private methods. 翻译是:还会举行听证会，会上各团体通过.... 可以看出in which定的是hearings，这里也不是非限定性从句，是什么用法呢? 另外我之前也见过这样的句子(具体忘记了，只说个大概) a book of much knowledge which...，which也定的是book不是knowledge