首先，因果关系词，其实有两类，一个是表示原因的：as、since、thanks to、as result of、because of、owing to、result from、due to、on account of、by virtue of、in that、attribute to;另一个是表示结果的：as a consequence、thus、hence、so、as a result、result in、contribute to、lead to、cause、breed、trigger

　　紧接着，我们来看托福阅读的句子简化题。这个题型要求考生快速地把文章段落中阴影长难句简化成一个意思不变的同义句，发现一个规律，那就是：原句的核心信息在正确选项中一定被同义改写了，但是句子中的重要的逻辑关系是不会变的。知道这个规律，解开这道题就变得简单了。

　　下面，我们来看TPO3 Desertification这篇文章的句子简化题：

　　The extreme seriousness of desertification results from the vast areas of land and the tremendous numbers of people affected, as well as from the great difficulty of reversing or even slowing the process.

　　A Desertification is a significant problem because it is so hard to reverse and affects large areas of land and great numbers of people.

　　B Slowing down the process of desertification is difficult because ofpopulation growth that has spread over large areas of land.

　　C The spread of deserts is considered a very serious problem that can be solved only if large numbers of people in various countries are involved in the effort.

　　D Desertification is extremely hard to reverse unless the population is reduced in the vast areas affected.

　　很多托福考生在做句子简化题时，习惯性地把待简化的句子翻译成中文，那样做其实不仅慢，而且很容易乱。

　　正确的做法是：

　　1. 找出句子的主谓宾，也就是谁做了什么，然后关注句子的逻辑关系。例题的主语是：seriousness of desertification，逻辑关系词是表示原因的：result from，所以我们可以优先看有表示原因的选项，他们中若有正确答案，那么剩下的选项就无需过问了。这样做不仅快，而且效率高。我们不难发现：A选项中有because;B选项中有because of;所以我们先看这两个选项。

　　2. 我们还发现原因用as well as相连，说明是两个原因，一个是影响land和people，一个是reverse和slow the process很难。A选项正确表达了句意，而B选项把原文中并列的两个原因变成了因果关系，很明显是错的。