托福阅读长难句精讲：介词+关系代词引导的定语从句

## 托福阅读长难句 We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human activities. ## 专家解析 ### 【子句拆分】 主句：We need therefore to know something in order to interpret with confidence the extent. 定语从句：To some extent recent changes are natural as opposed to being the result of human activities. 宾语从句：The climate can vary of its own accord. ### 【成分划分】 主句：We [主语] need therefore to know [谓语] something [宾语] in order to interpret with confidence the extent. [状语] 翻译：因此，为了能够有把握地做出解释这种程度，我们需要知道某事。 连接词：which 定语从句：To some extent [状语] recent changes [主语] are [系动词] natural [表语] as opposed to being the result of human activities. [状语] 翻译：与人类活动所造成的结果进行对比，最近的变化在某些程度上是自然发生的。 宾语从句：The climate [主语] can vary [谓语] of its own accord [状语] in order to interpret with confidence the extent. [状语] 翻译：气候能够自然而然发生变化。 ### 【全句翻译】 因此，我们需要了解气候变化有多少是自然而然发生的，以便能够有把握地解释最近的气候变化在多大程度上是自然发生的（与人类活动所造成的结果进行对比）。 ## 知识点梳理 ### 介词+关系代词引导的定语从句 在介词后作宾语的关系代词只有which 和whom。如先行词是物，引导词用which；如先行词是人，则引导词用whom。 一、看从句的动词选介词：所用介词需与定语从句中的动词构成固定搭配 例句1：The girl **with whom** you **work** is his girl friend. 例句2：The goals **for which** he had **fought** all his life no longer seemed important to him. 二、看从句的形容词选介词：所用介词需与定语从句中的形容词构成固定搭配 例句3：He referred me to some reference books **with which** I am not very **familiar**. 例句4：They will pass along their fresh impressions to the youth groups **in which** they are **active**. 三、看从句的名词选介词：所用介词需与定语从句中的名词构成固定搭配 例句5：I am sending you an inquiry, **to which** your prompt **attention** is highly appreciated. 四、看先行词选介词 这类情况，关系代词前面用什么介词与定语从句没有关系，而是与关系代词前面的先行词紧密相关，所选用的介词要与先行词构成固定搭配。 例句6：About a thousand species of animals are in danger of extinction, and **the rate at which** they are being destroyed has increased. 要想正确地使用介词，我们必须记住相关的介词短语搭配。常见的有：with ease，at the rate，in the direction，to the extent，to the degree，at the temperature，by the means，by the mode，in a culture，in practice 等等。