雅思阅读中的形容词性从句

        定语从句（Attributive Clauses）在句中作定语，其作用是修饰主句的某个名词性成分，相当于形容词，所以又称为形容词性从句。通常定语从句皆置于它所修饰的名词或代词之后，被修饰的名词或代词叫做先行词（antecedent），而引导定语从句的词称为关联词。
　　关联词常有3个作用：连接作用，引导定语从句；代替先行词；在定语从句中担当一个成分。关联词为关系代词和关系副词。关系代词在定语从句中可以用作主语、宾语、定语等；关系副词在定语从句中只用作状语。如：
　　★ One factor which may help ensure that some endangered languages do not die out completely is people's increasing appreciation of their cultural identity.（which may help ensure that some endangered languages do not die out completely是关系代词which引导的定语从句，用以修饰which的先行词factor, which在从句中用作主语）
　　★ And even in regions where new projects seem warranted, we must find ways to meet demands with fewer resources, respecting ecological criteria and to a smaller budget.（where new projects seem warranted是关系副词where引导的定语从句，用以修饰where的先行词regions, where在从句中用作地点状语）
　　定语从句一般紧跟在其先行词之后。如：
　　★ Food production has kept pace with soaring populations mainly because of the expansion of artificial irrigation systems that make possible the growth of 40% of the world's food.（关系代词that引导的定语从句紧跟其先行词artificial irrigation systems之后）
　　有时也可以与先行词分离。如：
　　★ A new teacher will come tomorrow, who will teach you Chinese.（关系代词who引导的定语从句与其先行词teacher分离）
　　用作关联词的关系代词有that, which, who, whom, whose, as等，但在此提醒考生们绝对没有“what”。who, whom, whose指人，who是主格，在定语从句中用作主语（在非正式英语中也可以用作宾语，并且用作宾语时可以省去不用）；whom是宾格，在定语从句中用作宾语（也可以省去不用）；whose是属格，在定语从句中用作定语（有时也可以指物）。如： (责任编辑：admin)