：如何利用关键字!托福阅读难度比较大的，大家在备考的时候需要花费一定的时间和精力进行备考，大家掌握一些托福阅读技巧还是很有必要的。尤其是掌握托福阅读中的关键字，会帮助大家顺利理解阅读文章的意思。
要读懂一个段落我们只需要抓住几个关键词而已。那么关键词怎么抓呢?一是看逻辑信号词;二是读句子的时候一定牢记只看主干!下面我们就以托福TPO25中的文章The Decline of Venetian Shipping为例，说说如何巧抓关键词。
TPO25-2 The Decline of Venetian Shipping：
Paragraph 2 This decline can be seen clearly in the changes that affected Venetian shipping and trade. First， Venic’s intermediary functions in the Adriatic Sea， where it had dominated the business of shipping for other parties， were lost to direct trading. In the fifteenth century there was little problem recruiting sailors to row the galleys (large ships propelled by oars)： guilds (business associations) were required to provide rowers， and through a draft system free citizens served compulsorily when called for. In the early sixteenth century the shortage of rowers was not serious because the demand for galleys was limited by a move to round ships (round-hulled ships with more cargo space)， with required fewer rowers. But the shortage of crews proved to be a greater and greater problem， despite continuous appeal to Venic’s tradition of maritime greatness. Even though sailors’ wages doubled among the northern Italian cities from 1550 to 1590， this did not elicit an increased supply.
以上算得上是托福阅读中较长的段落了，在快速阅读这个段落的时候我们要找的关键词是：逻辑信号词—如段落中所标示的first， but， this… 我们不难发现这些信号词所在的句子基本都是解题的信息点。那么在做题定位时不妨多加留意。当然，抓住这些关键词并不难，难在理解。
接下来我们就来看看理解这些句子时的关键词。每段话的首句是必定要读的。This decline can be seen clearly in the changes that affected Venetian shipping and trade。这是包含了一个定语从句的复杂句。先看到核心词changes，再看到Venetian shipping and trade。这篇文章接下来具体要写的内容就展露无遗，也就是威尼斯船业和贸易的变迁。
First，这当然是开始写shipping的标志了。Venice’s intermediary functions in the Adriatic Sea， where it had dominated the business of shipping for other parties， were lost to direct trading. 我们一直强调句子要读主干，那么简单地看这个句子就是Venice’s functions were lost， 核心词很显然是lost，也对应了整篇文章的主题 decline. 接下来两句写到了15和16世纪遇到的船员难招的问题。…there was little problem recruiting sailors to row the galleys (large ships propelled by oars)： guilds (business associations) were required to provide rowers， and through a draft system free citizens served compulsorily when called for. 这句话中有冒号的出现，阅读冒号之前的内容there was little problem;到下一句：the shortage of rowers was not serious because the demand for galleys was limited by a move to round ships (round-hulled ships with more cargo space)， with required fewer rowers. 这句中要看到的核心是not serious;再往后看到But….to be a greater and greater problem. 到这里意思应该已经一目了然了，就是讲威尼斯船业在招聘船员方面所遭遇的变迁：little problem—not serious —greater problem.
刚才我们讲了文章阅读部分要抓关键词，其实我们在阅读题目和选项时也是需要寻找关键词的。有些题目的选项是比较长的，四个选项看上去也差不多一段话了，所以一定要抓住关键词判断才行，如否定词、比较词和并列词。这些是快速浏览选项的第一步。再次也要看到题干和每个选项中能让我们快速定位到原文的关键词。我们还是以托福TPO25为例：
本文是托福阅读介绍：如何利用关键字。
TPO25-1 The Surface of Mars
Paragraph 5 As on the Moon， the extent of large impact cratering (i.e. craters too big to have been filled in by erosion since they were formed) serves as an age indicator for the Martian surface. Age estimates ranging from four billion years for Mars’s southern highlands to a few hundred million years in the youngest volcanic areas were obtained in this way。
According to paragraph 5， what have scientists been able to determine from studies of large impact cratering on Mars?
A. Some Martian volcanoes are much older than was once thought。
B. The age of Mars’s surface can vary from area to area。
C. Large impact craters are not reliable indicators of age in areas with high volcanic activity。
D. Some areas of the Martian surface appear to be older than they actually are。
划出选项中的关键词后，定位到原文迅速浏览发现原文中并无如A和D选项中的比较，C中的否定词not和原文是明显相矛盾的，故而选择B，而B选项对应的恰好是本段末句：Age estimates ranging from four billion years for Mars’s southern highlands to a few hundred million years in the youngest volcanic areas were obtained in this way。
根据以上分析，我们应该明白在阅读之时何为关键词。简单地讲有定位关键词和判断关键词。定位关键词包括题干及选项中的名词，还有就是段落中那些一直向你示好的逻辑信号词了，不要忘记用它们找到你解题需要的信息。判断关键词是选项中那些有特色的词汇，包括否定词，比较词或者是句子主干中的动词等，根据这些词和原文进行对应，至少有一半的选项可以迅速被排除。
以上就是托福阅读介绍：如何利用关键字，包括具体的实例分析，希望对你们有一定帮助。