在托福阅读考试中，在一般的主从句之间加入标点符号，往往可以插入更多的内容，从而呈现在我们面前一句超长的句子(词数35+甚至40+)。另外，对英文标点不熟悉的同学可能会被这类句子弄晕。不过其实，这种句子看懂之后其实比长难句的修饰成分要简单。
破折号用在托福文章中，主要是插入同位语的功能，如下例：
TPO22-2
The new candid photography—unposed pictures that were made when the subjects were unaware that their pictures were being taken—confirmed these scientific results, and at the same time, thanks to the radical cropping (trimming) of images that the camera often imposed, suggested new compositional formats.
这种情况破折号中的，内容可以视为破折号前名词的一个补充说明，理解句子结构时候完全可以把这部分扔掉，于是分析如下：
Topic：Candid photography confirmed scientific results.
Details：Method of candid photography(contents between dash lines)
New compositional formats thanks to the radical cropping of images(meanwhile)
英文中冒号的用法有一点值得注意，冒号前必须是具有完整结构的句子。具体用法在这里。
冒号之后的内容主要是解释说明冒号前的内容，如下例：
TPO24-3
Scholars believe that this cooperation allowed people to contend with a patchy environment in which precipitation and other resources varied across the landscape: if you produce a lot of food one year, you might trade it for pottery made by a distant ally who is having difficulty with crops—and the next year, the flow of goods might go in the opposite direction.
冒号后提出了一种可能的情况，用以佐证冒号前合作产生竞争的论断，于是分析如下：
Topic:Scholar believe cooperation allowed people to contend with the environment.
Details：Environment: precipitation and other resources varies across the landscape.
Illustrate how people act in this kind of cooperation by one example, say exchange spare crops with pottery.
分号的作用很简单，常用于分离没有连接词连接的句子。通常用在非常严肃正式的文体中，托福写作中不太推荐使用。在实际阅读中，我们只要把分号后面的内容看成另外一句句子即可，如下例：
TPO22-3 Since practically all the solar system's mass resides in the Sun, this similarity in chemistry means that chondrites have average solar system composition, except for the most volatile elements; they are truly lumps of nebular matter, probably similar in composition to the matter from which planets were assembled.
其他常见的标点符号还有括号等，限于篇幅这边就不介绍了。标点符号尽管看上去不起眼，但是在句子中它起到了很多的作用，也会帮助我们理解句子。预祝大家托福考试取得好成绩!
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