结构指示词，即Direction Words，在SAT阅读考试中的作用体现在三个方面：帮助预判focus或topic，帮助预判细节关系或者说是细节结构，帮助确定阅读速度的快慢。来看下面的例子：

Reports on an organization’s projects may fill several major functions at the same time. A report can be used to educate and gain support from key people and groups, to facilitate and inform decision-making about current and future projects, and to provide documentation for the organization’s records.

上面文字中的several是一个不定数词，它属于Classification & Listing这一类Direction Words，当它出现在观点句中或者结论句中的时候，它表明紧跟在它后面的名词或者名词短语就是下面文字的topic or focus，在这里我们知道下面文字的中心是报告的主要功能(major functions)。

其次通过several这一结构指示词，我们还可以判定下面的细节部分不是分类讨论结构就是列举结构。最后我们既然已经能够预判下文的中心和结构，也就自然能够加快阅读速度了，毕竟已知大意和目的的内容可以加快阅读。

下面是六类SAT阅读常见的结构指示词

Classification & Listing
category, classification, group, parts, types, characteristics, elements, kinds, sorts, ways, classes, features, numbers, 1,2,3,4, moreover, next, also, then, furthermore, etc.

Sequence of Process
first, now, later, second, after, stages, third, before, steps, next, finally, then, most, important, furthermore, when, last, etc.

Example
for example, for instance, to illustrate, such as, notably, to describe, specifically, perhaps the most, etc.

Definition
define, known as, we mean, is, that is, we can state, is defined as, the term means, etc.

Cause & Effect
because, for this reason, since, cause, on account of, why, contribute to, due to, as a result, in effect, therefore, consequently, result in, thus, hence, the outcome is, accordingly

Comparison & Contrast
compare, like/alike, resembles, likewise, similar, parallels, in comparison, in the same way/manner, although, however, on the other hand, as opposed to, but, instead, etc.

通过上面的介绍，我们就可以看到SAT阅读结构性指示词的内容和大家以前掌握的一些连接词非常相似，但是范围要更加广一些。大家可以在备考SAT阅读考试之前就对这些词汇进行熟悉和记忆，在备考中经过一段时间的练习之后就会有更好的掌握了。