一、理论常识
在复合句中作定语，修饰主句中某一名词或代词的从句。
结构：先行词+关系词(分为关系副词和关系代词)+从句
关系代词(that , who , which , whose , as)
关系副词(when , where , why , how)
定语从句分为限制性定语从句及非限制定语从句，限定从直接放在先行词后，非限定从与先行词之间要加逗号。
二、试题举例
例句1：
The Aswan Dam , for example , stopped the Nile flooding but deprived Egypt of the fertile silt that floods left-all in return for a giant reservoir of disease which is now so full of silt that it barely generates electricity .
【重点词汇解析】deprive sb. of sth. 剥夺某人某物;silt，n. 淤泥 v. (使)淤塞
【参考翻译】例如，阿斯旺大坝阻止了尼罗河的洪水侵袭，但是也夺去了埃及的洪水留下的肥沃淤泥---这一切换来的却是一个巨大的病态的水库，这个水库积满了淤泥，以至于几乎不能发电了。
例句2：
The second , by Joshua Greenberge , takes a more empirical approach to universality , identifying traits (particularly in word order) shared by many languages , which are considered to represent biases that result from cognitive constraints .
【重点词汇解析】empirical，adj. 经验主义的;result from 由……造成;cognitive，adj. 认知的
【参考翻译】第二个为此做出努力的人是约书亚·格林伯格，他采用经验主义的方法来研究普遍性，确认多种语言(尤其是语序方面的)共同特征，这些特征被认为是体现了由于认知局限性而带来的偏见。
例句3：
His function is analogous to that of a judge , who must accept the obligation of revealing in as obvious a matter as possible the course of reasoning which led him to his decision .
【重点词汇解析】analogous，adj. 类似的;reveal，vt. 揭露;reason，n. 理由 v. 推论
【参考翻译】他的职责类似于法官的职责，后者必须承担起这样的责任：用尽可能明显的方式来揭示让他做出决定的推理过程。
-