托福閱讀中推斷題解題技巧
托福閱讀的推斷題，相信大家在備考中，也整理了很對的解題方法。但是面對這些方法，到底哪些才更有價值，能夠幫助大家更好的來應對這類題型，在考試中更好的把握題型。下面小編為大家整理了詳細的內容，供大家參考!
托福閱讀推斷題的方法推薦
推斷題其實沒有想象中的那么難，因為托福文章有很清晰的邏輯架構，每個自然段往往是按照TS (Topic Sentence) + SD (Supporting details)展開的，而文章多半是按Introduction + Aspects + Attitudes展開的。只有明白了文章的寫作思路才能更好更快的做對題目，作者必定是按照一定的行文順序編排段落的，如果畫一個水平軸作為事件發(fā)展的順序，推斷題是讓你從這個軸上的某一個點去推測，無非就兩個方向，順著軸發(fā)展的方向或者逆著軸發(fā)展的方向，也就是我們接下來要說的用正向和逆向思維去解決推斷題。
OG上將推斷題定義為檢查考生對文章中強烈建議但絕不明說觀點(strongly implied but not explicitlystated in the text)的理解程度，屬于理解性題目，題目要求如下：
Paragraph 2 suggests which of the following about X?
Which of the following can be inferred from paragraph 2 about X?
According to paragraph 3, what do Y indicate about X?
According to paragraph 4, what does the author imply about X?
題干中有出現(xiàn)infer, imply, indicate或suggest這四個單詞，我們就判定這個題目為推斷題，那么推斷題應該如何解答呢?
第一步，判斷題型。我們拿到題目，看到上面四個單詞中的任何一個，心中就想著這是推斷題，推斷題的做題宗旨是文章強烈暗示，要通過文章內容進行合理推斷。
第二步，審清題干，原文定位。仔細閱讀題干，弄清題干內容，推斷方向，帶著題干核心信息到文章中準確定位。
第三步，推測+判斷。根據(jù)相關句進行正向或逆向的推理，最后擇優(yōu)而選，確定答案。
正向推斷：和事實信息題做題方法一樣，答案就是定位的句子的同義改寫。
逆向推斷：大致分為兩種，一種是時間，第二種是兩類事物的對比。
第一種，題干中往往會出現(xiàn)表示時間的信息，比如：after 1932, since early years of the 19thcentury. 例如TPO 20 Passage 1 Western Migration Q1:
Paragraph 1: The story of the westward movement of population in the US is, in themain, the story of the expansion of American agriculture of the development of new areas forthe raising of livestock and the cultivation of wheat, corn, tobacco, and cotton. After 1815, improved transportation enabled more and more western farmers to escape a self-sufficientway of life and enter a national market economy during periods when commodity prices werehigh, the rate of westward migration increased spectacularly.
What can be inferred from paragraph 1 about western farmers prior to 1815?
m They had limited their crop production to wheat, corn, tobacco and cotton.
m They were able to sell their produce at high prices
m They had not been successful in raising cattle.
m They did not operate in a national market economy.
題干中出現(xiàn)了兩個信息，一個是western farmers, 一個是prior to 1815, 帶著兩條信息去文中定位，定位在第一段第四行，但是文章中沒有提到1815年之前，只有1815年之后，答案其實很簡單，只要把1815年之后的內容看懂了，并且在這個內容前面加not即可。舉個簡單的例子，“從現(xiàn)在起Jessica是個姑娘”，“請問你能推斷出昨天Jessica怎么了么?”可能很多人想到“是不是Jessica做了變性手術?”，其實這就算過分推斷了，答案就是Jessica昨天不是個姑娘。言歸正題，文中說到，改善的交通使得越來越多的西部農民擺脫了自給自足的生活，并且進入了國家性的市場經(jīng)濟，那個時候貨物的價格很多，所以向西遷移的速率也大幅增長。
第二種：兩類事物的對比，往往文中會出現(xiàn)表示對比的關系詞：by contrast, unlike, while, whereas, on the contrary, in comparison to, distinct from, different from等詞。例如TPO 2中的TheOrigins of Cetaceans的第2題，讓考生推測關于early sea otters的，回到原文中定位，會發(fā)現(xiàn)關鍵句中存在著一個unlike, 說不像sea otters, 想象一下早期鯨類比較困難(not easy=difficult)，那我們逆推一下，不就是說想象早期sea otters長什么樣比較容易，正確答案中出現(xiàn)了not difficult, 所以這道題很簡單。
托福閱讀推斷題：認清類型，抓好關鍵詞
托福閱讀推斷題考察學生對文章深層信息的推測理解能力，所需要的信息都包含在文章中，但是沒有直接加以說明，需要考生從已知中推出。推理題是比較好辨認的一類題型，它的題干中常出現(xiàn)infer, imply , most likely (least likely) 或probably 等詞語。根據(jù)OG， 在IBT 閱讀3篇文章中，每篇會有0-2道這類問題，一次考試總共有3-4道推斷題。
推斷題一般可以分為有共性的推理題和無共性的推理題。所謂的有共性推理題就是說題干中有和原文內容相同的關鍵詞(也叫線索)，根據(jù)關鍵詞回原文定位，然后進行推理，大多數(shù)的推理題都屬于這類題目。對于無共性的推理題，也就是題干中無線索，一般使用排除法，即根據(jù)各個選項的關鍵詞回原文定位，通過排除法得出正確答案。返回原文找信息點、采用排除法是解決這兩類推理題的共同策略。
推理題的解題思路主要有以下三個方向：
1、一般對比推理：根據(jù)兩個事情的對比特征，問其中一個事物的特征，只要將與之形成對比的另外一個事情的特征否定掉就可以。
2、時間對比推理：在這種推理中，一般有兩個形成對比的時間段，它們所具有的特征一般相反。當題干問一個時間段的特征時，只要將與之相反的時間段的特征否定掉就可以了。
3、集合概念推理 ：一個大的集合的兩個方面形成對比，兩者之間存在著互補性關系，也就是一個的增加意味著另一個的減少。反之，相同。這個比較抽象，我們來看一個例子：
例如：Both the number and the percentage of people in the United States involved in nonagricultural pursuits expanded rapidly during the half century following the civil war, with some of the most dramatic increases occurring in the domains of transportation, manufacturing, and trade and distribution.
What can be inferred from the passage about the agricultural sector of the economy after the Civil War?
(A) New technological developments had little effect on farmers.
(B) The percentage of the total population working in agriculture declined.
(C) Many farms destroyed in the war were rebuilt after the war.
(D) Farmers achieved new prosperity because of better rural transportation.
文中指出：非農業(yè)人口的數(shù)量和比例都增加了。由此可知農業(yè)人口的數(shù)量和比例下降，所以(B)為正確答案。
三、解答這類題目需要注意的信息點：
1.日期和數(shù)字。
2.關鍵詞： 表示多少的副詞: many , some, much of, several , a few ,most …;情態(tài)動詞：may, can , could…;表示過去的：used to be , was, were , at one time, previously ;表示不是唯一的： not only ,not exclusively等。
總之，文中的關鍵詞，觀點，邏輯和平時的基本常識是解決這類問題的關鍵。
托福閱讀推理題的正向推理與逆向推理
正向推理
正向推理指的是最后的答案往往是和文章所描述的內容一致的，而這種特征一般視為“整體”和“部分”的一致性，所以正向推理也被稱為“整體與部分推理”。
正向推理包含兩種主要情形，一種叫做給定段里面沒有推理對象的情況，另外一種叫做有舉例引發(fā)的“整體與部分推理”。所謂“整體與部分推理”，就是文章里面講述一個特質是A，下面選項中的特征也是A，這個特質本身沒有變化。文章里面講什么特質，下面選項中就是什么特質，只不過一個是“整體”，一個是“部分”而已。
逆向推理
“逆向推理”又叫“取非式推理”，文章中講的是A，下面選項里最終答案是“非A”，此推理包含三種情形。
1.由新時間點引發(fā)的逆向推理
比如“now”表示現(xiàn)在，含有典型的暗轉折含義。事實上，凡是時間點概念，都暗示著轉折。比如說：1999年澳門回歸了，這意味著1999年之前澳門沒有回歸。這條原則可能聽起來怪怪的，但意義重大，以后我們做托福文章要比其他沒有經(jīng)歷過嚴格訓練的同學多長一個心眼，但凡是有時間點出現(xiàn)，就意味著前后的特質不一致，而這恰好是考點。
2.由新地點引發(fā)的逆向推理
事實上，它和第一點的內涵是一致的，可以被統(tǒng)稱為“分類取非”。在文章中經(jīng)常會出現(xiàn)把一個大類分成兩個小類的情況，比如文章里面講述生物分為兩類，一類是動物，一類是植物，這時文章里面會談到動物和植物的“不同點”而不會是“相同點”。
3.由特定詞引發(fā)的逆向推理
這一類詞包括unlike、without以及所有能夠表示“比例”的詞等。一般推理題只要找準用來推理的句子，然后按照上面兩種方法來做就不會有什么問題了。
只要掌握了這些技巧，當你在做托福閱讀時，也能像偵探一樣進行“推理”了。
托福閱讀推理題的對比取反情況
解答推理題應從識別題型入手。推理題題干中常見表示推理或暗示的詞匯：infer，imply，indicate，suggest。然后，仔細閱讀題干。最后，根據(jù)題干信息研讀文章信息以做出推理。
接下來我們通過一些例題來深入解析推理題中對比取反的情況。
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.
根據(jù)題干信息flatboats and keelboats對應到原文句子Steamboats were not only faster but also transported upriver freight for about one tenth of what it had previously cost on hand-propelled keelboats. 從句子里steamboat以及keelboats之間的faster 以及one tenth of很容易得出B選項。解出答案之后，希望大家思考，這樣一道推理題透露了出題人設置題目時的邏輯思維，那就是信息的對比，而且有對比的時候，答案往往會取反面。
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.
根據(jù)題干信息commensalism對應到原文句子There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism.該句得不出答案，接著看到The first and the third can be key factors in the structure of a biological community;該句告訴我們first and third指代上句中的parasitism和mutualism, 而題干中被問及的commensalism(共棲)恰是三者之中剩余的部分，根據(jù)例一中出題人對于對比取反的邏輯設置，顯然該題同樣取反，既然文中給出一三重要，那么強烈暗示的就是處于第二的commensalism不重要，所以選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.
同樣根據(jù)題干信息oxygen-16對應到原文During glaciations, the lighter oxygen-16 has a greater tendency to evaporate from the ocean surface than the heavier oxygen-18 does. 句中給出during glaciations的時候oxygen-16會蒸發(fā)離開，題干問什么時候oxygen-16 were deposited, 同樣還是對比取反，即not during glaciations，對應選項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.
通過以上的例子，相信大家已經(jīng)熟悉了推理題中對比取反的邏輯思維。那么最后這一道題，是否能夠應用講解的規(guī)律順利得出正確答案呢?
首先讀題干，很多考生會選擇Agassiz and other geologists這一信息去對應原文，結果發(fā)現(xiàn)無法根據(jù)文中對應信息得出正確答案。此時要牢記對比取反的邏輯思維，重新審題發(fā)現(xiàn)了of his time這一時間短語與文中的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構成對比關系。所以根據(jù)對比取反的邏輯，既然我們現(xiàn)在才精確知道冰川形成的時間，那么在當時是不知道的，順利選出B選項。
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