标题: Mankind must estabilsh a set of positive values with which to secure its own sur [打印本页] 作者: 匿名 时间: 2013-12-27 08:34 标题: Mankind must estabilsh a set of positive values with which to secure its own sur Mankind must estabilsh a set of positive values with which to secure its own survival. 这是一个定语从句吗，怎么没主语，而且又像一个不定式的状语从句