在托福阅读的课程中，常常被同学们问到的是如何提高阅读和做题效率的问题，因为大部分同学无法拿到阅读高分的核心原因是时间不够无法读全文章，直接做题又感觉患得患失地不知道选择的答案是否正确符合文章意思，这往往使得我们在备战阅读考试的效果大打折扣。

由于提高阅读速度是一个需要长期训练的过程，为了让同学们短期提高一些阅读分数和学习效果，我们来试试对比一些方法来高效的发现题目的切入点并且解决问题拿到分数。

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 inferredfrom paragraph 1?

 ○It excludes interactions betweenmore than two species.

 ○It makes it less likely for specieswithin a community to survive.

 ○Its significance to the organizationof biological communities is small.

 ○Its role in the structure ofbiological populations is a disruptive one.

✔解法1：

初学者在看到这样题目的时候，会先把文章看完甚至翻译一遍，认为理解了自然就能选对答案。这是正确率最高最靠谱的做法，但最大的缺陷是考试时无法在短时间内理解文章并且做完题目。所以在阅读能力不是很强的时候，尽量不要使用看完理解再做题的方法。

✔解法2：

定位规律

•  题干关键词：commensalism

•  文中定位点：There are three main types ofsymbiotic relationships: parasitism, commensalism,and mutualism.有三种共生关系：寄生、共生、互利共栖。说的是题干关键词本身的内容，无法对应选项。

•  再往后读啊读啊读啊……理论上来说看到这里应该能得到答案了，但是……但是……看看选项？

○共生关系不包括超过两个物种之间的相互作用

○共生关系使得物种在生物团体中难以生存

○共生关系在生物群体中的重要性是小的

○共生关系在生物结构中的角色是引起混乱的

 选哪个？！正确答案是哪个啊？

这里我们要学的是一个小套路，我们把文中内容和选项都理解后得到这样的一个逻辑：

文章：第一个和第三个在一个生物团体结构中是重要的；意思是，所有的有机体居住在一起并且在特定的区域相互作用。

推理模式：第一个（寄生）和第三个（互利共栖）在一个生物团体结构中是重要的→第二个（共生）是不重要的

☞所以选C

这个切入点你发现了吗？

但这样分析题目，对我们来说有什么实际的意义呢？同学们，这篇文章的核心就是希望大家能高效的发现题目的切入点并且解决问题。于是，对于这道题来说发现一个能够广泛使用的规律，比起选出正确答案更有意义：

让我们聊聊刚才在题目中的推理模式：第一个（寄生）和第三个（互利共栖）在一个生物团体结构中是重要的→第二个（共生）是不重要的。

这个推理模式我叫做反义推理（有些老师也叫做反向推理、取非，意思一致），是托福阅读推理题常用的推理模式，并且在细节题、否定事实信息题（NOTEXCEPT）和判断其他题型错误选项的时候经常使用，也是最常见的一种思维模式。反义推理的核心来自于归约（reduction），意思是当未知量与已知量看上去无法匹配的时候，在二者之间搭上一个桥梁来使得找答案变得更简单。

With question such as these clearly before them, the scientists aboard the Glomar Challenger processed to the Mediterranean to search for the answers.On August 23, 1970, they recovered a sample. The sample consisted of pebbles of hardened sediment that had once been soft, deep-sea mud, as well as granules of gypsum and fragments of volcanic rock. Not a single pebble was found that mighthave indicated that the pebbles came from the nearby continent. In the days following, samples of solid gypsum were repeatedly brought on deck as drilling operations penetrated the seafloor. Furthermore, the gypsum was found to possess peculiarities of composition and structure that suggested it had formed on desert flats. Sediment above and below the gypsum layer contained tiny marine fossils, indicating open-ocean conditions. As they drilled into the central and deepest part of the Mediterranean basin, the scientists took solid,shiny, crystalline salt from the core barrel. Interbedded with the salt were thin layers of what appeared to be wind blown silt.

4．Which of the following can beinferred from paragraph 3 about the solid gypsum layer?

○It did not contain any marine fossil.

○It had formed in open-ocean conditions.

○It had once been soft, deep-sea mud.

○It contained sediment from nearby deserts.

✔解析：

这道题很容易，和上一题是同样的套路

•  题干关键词：the solid gypsum layer

•  文中定位点：Sediment above and below the gypsumlayer contained tiny marine fossils, indicating open-ocean conditions.

•  利用反义推理：在石膏层上面和下面的沉积层中包含小海洋化石→石膏层不包含海洋化石

☞所以选A

而在我们熟练了在一个完整概念下不同因素之间的反义推理后（例如整体是【A,B,C】, 文中说AB重要则C不重要，AB有东西则C没有），将完整概念拓展到时间点前后区分概念会使得做题变得更加的简单： 

【Paragraph 2】Yet this most fundamental standard of historical periodization concealsa host of paradoxes. Nearly every movie theater, however modest, had a piano ororgan to provide musical accompaniment to silent pictures. In many instances,spectators in the era before recorded sound experienced elaborate auralpresentations alongside movies' visual images, from the Japanese benshi(narrators) crafting multivoiced dialogue narratives to original musicalcompositions performed by symphony-size orchestras in Europe and the UnitedStates. In Berlin, for the premiere performance outside the Soviet Union of TheBattleship Potemkin, film director Sergei Eisenstein worked with Austriancomposer Edmund Meisel (1874-1930) on a musical score matching sound to image;the Berlin screenings with live music helped to bring the film its wideinternational fame.

5. Paragraph 2 suggests which of the following about Eisenstein’s film The Battleship Potemkirf?

○The film was not accompanied by sound before its Berlin screening.

○The film was unpopular in the Soviet Union before it was screened in Berlin.

○Eisenstein’s film was the first instance of collaboration between a director and a composer.

○Eisenstein believed that the musical score in a film was as important as dialogue.

✔解析：

•  题干关键词：Eisenstein’s film The Battleship Potemkirf，大写字母很容易找

•  文中定位点：In Berlin, for the premiereperformance outside the Soviet Union of The Battleship Potemkin, film directorSergei Eisenstein worked with Austrian composer Edmund Meisel (1874-1930) on amusical score matching sound to image; the Berlin screenings with live musichelped to bring the film its wide international fame.

•  利用反义推理：在柏林首次公演→在柏林之前没有演过

☞所以选A

对我们来说，掌握了时间点前后不一致，可以使用反义推理这个方法，能让我们更快的得到答案： 

The areas covered by this material were so vast that the ice that deposited it must have been a continental glacier larger than Greenland orAntarctica. 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, peoplebegan 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 ofthe 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 yearsago. Along the east coast of the United States, the southernmost advance ofthis ice is recorded by the enormous sand and drift deposits of the terminal moraines that form Long Island and Cape Cod.

5.It can be inferred from paragraph 2 that Agassiz and other geologistsof his time were not able to determine

 ○which geographic regions had beencovered with ice sheets in the last ice age

 ○the exact dates at which drifts hadbeen deposited during the last ice age

 ○the exact composition of the driftslaid during the last ice age

 ○how far south along the east coastof the United States the ice had advanced during the last ice age

✔解析：

•  题干关键词：Agassiz and other geologists of histimewere not able to determine

•  文中定位点：We now know the age of theglaciation accurately from radiometric dating of the carbon-14 in logs buriedin the drift.

•  利用反义推理：Wenow know ……→Agassiz and other geologists of histimewere not able to determine

☞所以选B

It was not until the Cambrian period, beginning about 600 million yearsago, that a great proliferation of macroscopic species occurred on Earth andproduced a fossil record that allows us to track the rise and fall ofbiodiversity. Since the Cambrian period, biodiversity has generally risen, butthere have been some notable exceptions. Biodiversity collapsed dramaticallyduring at least five periods because of mass extinctions around the globe. Thefive major mass extinctions receive most of the attention, but they are onlyone end of a spectrum of extinction events. Collectively, more species wentextinct during smaller events that were less dramatic but more frequent. Thebest known of the five major extinction events, the one that saw the demise ofthe dinosaurs, is the Cretaceous-Tertiary extinction.

2. Paragraph 1 supports which of the following statements about life onEarth before the Cambrian period?

○Biodiversity levels were steady, asindicated by the fossil record.

○Levels of biodiversity could not betracked.

○The most dramatic extinction episodeoccurred.

○Few microscopic species existed.

 ✔解析：

•  题干关键词：before the Cambrian period?

•  文中定位点：It was not until the Cambrian period, beginning about 600 million years ago, that a great proliferation ofmacroscopic species occurred on Earth and produced a fossil record that allowsus to track the rise and fall of biodiversity.

•  利用反义推理：It was not until the Cambrian period……allows us to track the riseand fall of biodiversity→Levels of biodiversity could not betracked.

☞所以选B 

反义推理这个模式还可以被用在NOTEXCEPT题当中：

Five centuries later, about 7700B.C., a new village rose on the mound.At first the inhabitants still hunted gazelle intensively. Then, about 7000B.C., within the space of a few generations, they switched abruptly to herdingdomesticated goats and sheep and to growing einkorn, pulses, and other cerealgrasses. Abu Hureyra grew rapidly until it covered nearly 30 acres. It was aclose-knit community of rectangular, one-story mud-brick houses, joined bynarrow lanes and courtyards, finally abandoned about 5000 B.C.. Many complexfactors led to the adoption of the new economies, not only at Abu Hureyra, butat many other locations such as 'Ain Ghazal, also in Syria, where goat toebones showing the telltale marks of abrasion caused by foot tethering (binding)testify to early herding of domestic stock.

10.According to paragraph 5, after 7000 B.C. the settlement of AbuHureyra differed from earlier settlements at that location in all of thefollowing EXCEPT

 ○the domestication of animals

 ○the intensive hunting of gazelle

 ○the size of the settlement

 ○the design of the dwellings

✔解析：

•  题干关键词：after 7000 B.C

•  文中定位点：Then, about 7000 B.C……但我的思考是，之后的内容对应选项则会成为正确的内容，而题目需要我们找到错误的内容并且选出来，那么，7000BC之前的内容如果对应选项，就应该是错误的并且可以被选出来了，根据这个想法我们往前看

•   Five centuries later, about7700B.C., a new village rose on the mound. At first the inhabitants stillhunted gazelle intensively.

☞对应答案B

During wakefulness, breathing is controlled by two interacting systems.The first is an automatic, metabolic system whose control is centered in thebrain stem. It subconsciously adjusts breathing rate and depth in order toregulate the levels of carbon dioxide (CO2) and oxygen (O2), and the acid-baseratio in the blood. The second system is the voluntary, behavioral system. Itscontrol center is based in the forebrain, and it regulates breathing for use inspeech, singing, sighing, and so on. It is capable of ignoring or overridingthe automatic, metabolic system and produces an irregular pattern of breathing.

2.According to paragraph 2, all of the following are true of thevoluntary breathing system EXCEPT:

○It has its control center in thebrain stem.

○It controls breathing for a numberof activities during wakefulness.  

○It is able to bypass the automatic system.

○It produces an irregular breathing pattern.

✔解析：

•  题干关键词：the voluntary breathing system

•  文中定位点：The second system is the voluntary,behavioral system.

•  反义推理：看到second则一定有first，思考是first的内容对应选项则一定不符合second的内容所以文中The first is an automatic, metabolic systemwhose control is centered in the brain stem.