托福閱讀8大題型解題策略之推斷題解題方法

　　推斷題，顧名思義，就是要做一定的推理，于是，同學(xué)們沸騰了，推理啊!誰不會(huì)啊!毛利小五郎上身!神探夏洛克附體!我就是柯南!五花八門，無奇不有，無孔不入，似乎每個(gè)選項(xiàng)都很有道理!于是，陷入死循環(huán)，等到再遇到這樣的題型，只能憑感覺，看到哪個(gè)選項(xiàng)順眼，就選擇哪個(gè)選項(xiàng)。然后，你就錯(cuò)了。

　　那么，今天我們從一個(gè)最簡單的角度來攻破推斷題，即反向推理。

　　反向推理，指當(dāng)事物A和事物B特征相反，現(xiàn)在已知事物A特征，問B特征時(shí)，那么B等于A的反向特征。而其中，最為明顯的在于時(shí)間前后的推理。我們先看一道非常簡單的真題。

　　【Paragraph 1】The story of the westward movement of population in the United States is, in the main, the story of the expansion of American agriculture—of the development of new areas for the 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-sufficient way of life and enter a national market economy. During periods when commodity prices were high, the rate of westward migration increased spectacularly. "Old America seemed to be breaking up and moving westward," observed an English visitor in 1817,during the first great wave of migration. Emigration to the West reached a peak in the 1830's. Whereas in 1810 only a seventh of the American people lived west of the Appalachian Mountains, by 1840 more than a third lived there.

　　1.What can be inferred from paragraph 1 about western farmers prior to 1815?

　　A.They had limited their crop production to wheat, corn, tobacco, and cotton.

　　B. They were able to sell their produce at high prices.

　　C. They had not been successful in raising cattle.

　　D. They did not operate in a national market economy.

　　本題中有非常明顯的信息可以幫助我們定位，即年份數(shù)字“1815”，定位到原文After 1815 improved transportation enabled more and more western farmers to escape a self-sufficient way of life and enter a national market economy. 在1815年之后，改進(jìn)的交通方式使得越來越多的西部弄明逃開了自給自足的生活方式，進(jìn)入了國家市場經(jīng)濟(jì)。這是講在1815年之后的事情，而題干中問的是“prior to 1815”，即在1815年之前，那么根據(jù)反向推理原理，直接對(duì)1815年之后的事情取反，即“在1815年之前，交通方式還未改進(jìn)，人們是自給自足的生活方式，還未進(jìn)入國家市場經(jīng)濟(jì)”，直接對(duì)應(yīng)D選項(xiàng)。所以本題選擇D選項(xiàng)。

　　在托福閱讀考試當(dāng)中，時(shí)間上的反向推理題還有很多很多，難度也可能會(huì)更高，比如，我們?cè)賮硪坏李}。

　　【Paragraph 1】It was not until the Cambrian period, beginning about 600 million years ago, that a great proliferation of macroscopic species occurred on Earth and produced a fossil record that allows us to track the rise and fall of biodiversity. Since the Cambrian period, biodiversity has generally risen, but there have been some notable exceptions. Biodiversity collapsed dramatically during at least five periods because of mass extinctions around the globe. The five major mass extinctions receive most of the attention, but they are only one end of a spectrum of extinction events. Collectively, more species went extinct during smaller events that were less dramatic but more frequent. The best known of the five major extinction events, the one that saw the demise of the dinosaurs, is the Cretaceous-Tertiary extinction.

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

　　A. Biodiversity levels were steady, as indicated by the fossil record.

　　B. Levels of biodiversity could not be tracked.

　　C. The most dramatic extinction episode occurred.

　　D. Few microscopic species existed.

　　本題中我們可以根據(jù)專業(yè)詞匯“Cambrian period”定位到It was not until the Cambrian period, beginning about 600 million years ago, that a great proliferation of macroscopic species occurred on Earth and produced a fossil record that allows us to track the rise and fall of biodiversity. 直到六億年前的寒武紀(jì)時(shí)期，肉眼可見的生物才在地球上大量出現(xiàn)并產(chǎn)生可以讓我們了解物種多樣性興衰的化石。可是題干中用的是“before the Cambrian period”，即寒武紀(jì)之前，那么只要將原文中寒武紀(jì)之后的內(nèi)容取反，即“在寒武紀(jì)之前，肉眼可見的生物還沒有大量出現(xiàn)，我們還不能了解物種的多樣性”，對(duì)應(yīng)B選項(xiàng)。

　　所以，當(dāng)問題或原句信息中出現(xiàn)了明確的在某種時(shí)間前后發(fā)生的事件時(shí)，大家要注意作者已經(jīng)在給出一定的提示了，我們可以通過前后的信息進(jìn)行推斷。

　　從這個(gè)角度看來，其實(shí)，閱讀的推斷題，很可愛對(duì)嗎?只要我們了解它的出題原理和作者的出題意圖，明確原文中句子間的邏輯關(guān)系，其實(shí)推斷題并不是為難廣大考生的絆腳石，而是幫助我們?nèi)〉瞄喿x高分、提升閱讀理解能力的好工具!