介词+关系代词“介词+关系代词”引导的定语从句是定语从句的一种复杂形式，这类定语从句的关系代词主要有which ,whom , whose , 它们既可以引导限定性定语从句，也可以引导非限定性定语从句。关系代词前该选用什么样的介词，要根据不同的语境、习语、惯用法等来决定。1 介词选择的主要标准1. 介词与定语从句的先行词是一种习惯性搭配Human facial expressions differ from those animals in the degree to which they can be controlled on purpose.人类的面部表情和动物的面部表情就可控制的程度来说是不一样的。( to a degree )The gentleman about whom you told me yesterday proved to be a thief.你昨天告诉我的那个绅士被证明是个小偷。( tell sb. about sb./ sth. )The English play in which my students acted at the
