Ukraine has been the subject of several of our By Invitation columns—The Economist’s equivalent of op-eds—of which we publish several each week and which have become increasingly popular in recent months.
请老师看一下,这里是不是非限制性从句,这里的which指代的是前面什么成分呢?
《高考英语备考1号·速效编》
《高考英语备考1号·写作编》
《高中英语晨读晚记》
《高中英语错题笔记》
《零起点考大学英语》