职称英语综合类考试：
定语从句(Attributive Clause)这是出现在阅读题型中最多的从句！重要！
定语从句：在句中做定语，修饰一个名词或代词。
先行词：被定语从句修饰的名词，词组或代词。
关系词：引导定语从句的词；一般紧跟在先行词后引出定语从句。分为关系代词和关系副词。
关系代词有：who， whom， whose， that， which等。
关系副词有：when， where， why等。
关系词常有3个作用：1，引导定语从句。2，代替先行词。3，在定语从句中担当一个成分。
例如：
Once upon a time， there was a king (who had a small kingdom)。
先行词 关系词
For one thing， the tigers ( that were kept in the zoo) were often used in court.
先行词 关系词
There came out a young lady ( whose hair was golden)。
先行词 关系词
They would meet on the night ( when there was a full moon in the sky)。
关系代词引导的定语从句
关系代词在定语从句中作主语时，从句谓语动词的人称和数要和先行词保持一致。
(1) A teacher is a person who passes knowledge to the student.
(2) The book that is on the desk was written by Yao Ming.