考向一 非限制性定语从句非限制性定语从句是对意义已经非常明确的先行词给予补充、说明,删去非限制性定语从句,主句的意思仍是概念清晰、结构完整的。非限制性定语从句的引导词有who,whom,which,whose,as,when,where等,that不可用于引导非限制性定语从句,从句之前要用逗号。先行词指人,则用who,whose,which等;先行词指物,要用which;先行词表时间或者地点,并在句中作时间状语或者地点状语时要用when或者where引导。一、使用非限制性定语从句的情况:1. 关系代词指代整个主句时,使用非限制性定语从句。You did a lot for me, for which I was grateful.你为我做了许多,对此我很感激。The Diaoyu Island belongs to China, as is known to us.众所周知,钓鱼岛属于中国。A middle-aged woman killed her husband, which frightened me very much.一个中年女