一、题型分类
对于托福阅读来说，词汇是根本。在阅读中词汇题(vocabulary questions)的数量很多，每篇存在三至五题不等。
接下来就是阅读中的句子。句子细节在托福中的考察形式和内容相比词汇更为深入。有对于单个句子结构和主干意思理解做出的考察，即句子简化题(sentence simplification questions)。有对于文中明确表述的细节信息的考察和理解，即事实信息题(factual information questions)。还有对于文中明确表述信息真伪的识别和理解，也就是否定事实信息题(negative factual information questions)。除此之外，阅读还会考察对于文中强烈暗示而未明确表述的信息的识别和理解能力，即推理题(inference questions)。
在阅读中，对于段落的考察往往侧重于句子之间的关系。句与句之间的连接往往会有名词的重复以及代词的指代，所以有了指代题(reference questions)。内容的衔接除了代词指代之外，还有逻辑关系的递进，所以又有了修辞目的题(rhetorical purpose questions)。如果说指代题和修辞目的题是对于句间关系的识别的话，那么句子插入题(insert sentence questions)则是两者的升级版，是对于句间关系的逻辑的应用。
当然，托福阅读也涉及篇章中段落的主旨以及段间的关系的考查。若是顺承的关系往往出的是总结题(prose summary questions)，若是对比分类的关系往往出的是表格题(fill in a table questions)。
二、题型难度
通过以上的分类讲解，相信大家对于托福阅读十大题型考察的能力有了了解。那么十大题型里，哪种题型相对比较难呢?如果说其他题型是通过词汇积累或者对于文章里的信息的透彻理解就可以掌握的话，那么更侧重于考察出题人的逻辑思维模式的题型就是推理题了。
我们再来看一下托福官方指南里对于推理题的表述：对于文中强烈暗示而未明确表述信息的识别和理解。大家重点关注强烈暗示这几个词，言下之意就是通过一些相关信息的表述来传递内在的意思，所以体会出题人传达相关信息的模式就变成了解题的关键。
三、推理题中的对比取反
解答推理题应从识别题型入手。推理题题干中常见表示推理或暗示的词汇：infer，imply，indicate，suggest。然后，仔细阅读题干。最后，根据题干信息研读文章信息以做出推理。
接下来我们通过以下四个例子来层层深入解析推理题中对比取反的情况。
1. Paragraph: Two other developments presaged the end of the era of turnpikes and started a transportation revolution that resulted in increased regional specialization and the growth of a national market economy. First came the steamboat; although flatboats and keelboats continued to be important until the 1850s, steamboats eventually superseded all other craft in the carrying of passengers and freight. Steamboats were not only faster but also transported upriver freight for about one tenth of what it had previously cost on hand-propelled keelboats.
1. Which of the following can be inferred from the paragraph about flatboats and keelboats?
A. They ceased to be used as soon as the first turnpikes were built.
B. They were slower and more expensive to operate than steamboats.
C. They were used for long-distance but not for regional transportation.
D. They were used primarily on the Erie Canal.
根据题干信息flatboats and keelboats对应到原文句子Steamboats were not only faster but also transported upriver freight for about one tenth of what it had previously cost on hand-propelled keelboats. 从句子里steamboat以及keelboats之间的faster 以及one tenth of很容易得出B选项。解出答案之后，希望大家思考，这样一道推理题透露了出题人设置题目时的逻辑思维，那就是信息的对比，而且有对比的时候，答案往往会取反面。
2. Paragraph: A symbiotic relationship is an interaction between two or more species in which one species lives in or on another species. There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism. The first and the third can be key factors in the structure of a biological community – that is, all the populations of organisms living together and potentially interacting in a particular area.
1. Which of the following statements about commensalism can be inferred from the paragraph?
A. It excludes interactions between more than two species.
B. It makes it less likely for species within a community to survive.
C. Its significance to the organization of biological communities is small.
D. Its role in the structure of biological populations is a disruptive one.
根据题干信息commensalism对应到原文句子There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism.该句得不出答案，接着看到The first and the third can be key factors in the structure of a biological community;该句告诉我们first and third指代上句中的parasitism和mutualism, 而题干中被问及的commensalism(共栖)恰是三者之中剩余的部分，根据例一中出题人对于对比取反的逻辑设置，显然该题同样取反，既然文中给出一三重要，那么强烈暗示的就是处于第二的commensalism不重要，所以选C。
3. Paragraph: Isotopic analysis of shells allowed geologists to measure another glacial effect. They could trace the growth and shrinkage of continental glaciers, even in parts of the ocean where there may have been no great change in temperature – around the equator, for example. The oxygen isotope ratio of the ocean changes as a great deal of water is withdrawn from it by evaporation and is precipitated as snow to form glacial ice. During glaciations, the lighter oxygen-16 has a greater tendency to evaporate from the ocean surface than the heavier oxygen-18 does. Thus, more of the heavy isotope is left behind in the ocean and absorbed by marine organisms. From this analysis of marine sediments, geologists have learned that there were many shorter, more regular cycles of glaciation and de-glaciation than geologists had recognized from the glacial drift of the continents alone.
1. It can be inferred from paragraph 5 that foraminifera fossil shells containing calcite with high percentages of oxygen-16 were deposited at times when…
A. polar ice extended as far as equatorial regions of land and sea.
B. extensive glaciation was not occurring.
C. there were no great increases in ocean temperature.
D. there was heavy snowfall on continental glaciers.
同样根据题干信息oxygen-16对应到原文During glaciations, the lighter oxygen-16 has a greater tendency to evaporate from the ocean surface than the heavier oxygen-18 does. 句中给出during glaciations的时候oxygen-16会蒸发离开，题干问什么时候oxygen-16 were deposited, 同样还是对比取反，即not during glaciations，对应选项B。
4. Paragraph 2: The areas covered by this material were so vast that the ice that deposited it must have been a continental glacier larger than Greenland or Antarctica. Eventually, Agassiz and others convinced geologists and the general public that a great continental glaciation had extended the polar ice caps far into regions that now enjoy temperate climates. For the first time, people began to talk about ice ages. It was also apparent that the glaciation occurred in the relatively recent past because the drift was soft, like freshly deposited sediment. We now know the age of the glaciation accurately from radiometric dating of the carbon-14 in logs buried in the drift. The drift of the last glaciation was deposited during one of the most recent epochs of geologic time, the Pleistocene, which lasted from 1.8 million to 10,000 years ago. Along the east coast of the United States, the southernmost advance of this ice is recorded by the enormous sand and drift deposits of the terminal moraines that form Long Island and Cape Cod.
1. It can be inferred from paragraph 2 that Agassiz and other geologists of his time were not able to determine…
A. which geographic regions had been covered with ice sheets in the last ice age.
B. the exact dates at which drifts had been deposited during the last ice age.
C. the exact composition of the drifts laid during the last ice age.
D. how far south along the east coast of the United States the ice had advanced during the last ice age.
通过以上的例子，相信大家已经熟悉了推理题中对比取反的逻辑思维。那么最后这一道题，是否能够应用讲解的规律顺利得出正确答案呢?
首先读题干，很多考生会选择Agassiz and other geologists这一信息去对应原文，结果发现无法根据文中对应信息得出正确答案。此时要牢记对比取反的逻辑思维，重新审题发现了of his time这一时间短语与文中的We now know the age of the glaciation accurately from radiometric dating of the carbon-14 in logs buried in the drift.一句里的now构成对比关系。所以根据对比取反的逻辑，既然我们现在才精确知道冰川形成的时间，那么在当时是不知道的，顺利选出B选项。
在托福阅读中，希望考生可以通过分析真题仔细体会出题人的思维逻辑，掌握考试规律，这样才能百战百胜。
在托福阅读十大经典题型中，推理题的难度排行仅次于文章内容小结题，要提高托福阅读推理题的解题正确率，首要前提就是要能够准确找到该题的推理依据。
下面来分享一下关于在解答托福阅读推理题时，如何准确找到推理依据的步骤。
步骤一：审题
通过审题，确定本题的推理对象；
步骤二：回原文中锁定推理对象的位置
这时候又分两种情况，如果推理对象存在于原文某个句子中的其中一个分句或一个部分，则推理依据就在本句剩下的内容中;如果推理对象存在于原文一个完整的句子中，则推理依据需要结合上下文。
比如下面这道题：(TPO24)
By whatever means,a lake is constantly gaining water and losing water:its water does not just sit there,or,anyway,not for long.This raises the matter of a lake’s residence time.The residence time is the average length of time that any particular molecule of water remains in the lake,and it is calculated by dividing the volume of water in the lake by the rate at which water leaves the lake.The residence time is an average;the time spent in the lake by a given molecule(if we could follow its fate)would depend on the route it took:it might flow through as part of the fastest,most direct current,or it might circle in a backwater for an indefinitely long time.
It can be inferred from paragraph 4 that the length of time a given molecule of water remains in a lake
A.depends entirely upon the average speed of a lake's currents
B.can be measured by the volume of the lake alone
C.can be greater or lesser than the residence time
D.is similar to the length of time all other molecules remain in that lake
首先审题，我们知道推理对象为the length of time a given molecule of water remains in a lake，然后通过定位，找到原文包含推理对象的句子，即原文最后一句话的后半句，“The residence time is an average;the time spent in the lake by a given molecule(if we could follow its fate)would depend on the route it took:it might flow through as part of the fastest,most direct current,or it might circle in a backwater for an indefinitely long time.”
本句话以分号分成了前后两个分句，因此前一个分句也需要分析。前一个分句，即“The residence time is an average，停留时间是平均的”，这个信息点需要记住，接下来再把后半句看完。后半句，即“the time spent in the lake by a given molecule would depend on the route it took，一分子的水停留在湖里的时间取决于它所走的路线”，隐含意思即水停留在湖里的时间是不固定的，走的路线是直线，则停留时间短，走的路线是循环的，则停留时间就长。结合前一个分句，可得出结论，一分子的水停留在湖里的时间可能比residence time长，也可能比它短，故答案为C。
如何应对托福阅读推理题？只要结合上下文寻找推理依据，如果包含推理对象的句子是不完整的，则推理依据蕴藏在本句中。