逻辑关系在托福阅读中的应用

在英语学习中不难发现西方人比较注重抽象思维，从古希腊亚里士多德开始，就一直注重哲学思辨。在语言中，英语多使用抽象表达，大量使用抽象名词。同时，英语注重形合，在表达的时候，逻辑非常严密，先陈述主要思想，再延伸出去。就句子层次而言，英语有着严谨的主谓结构，起到提纲挈领的作用，表达主要信息，再陈述其他辅助性信息，丰富句意的表达。扩展到段落及篇章亦是如此，信息的展开非常有条理性，逻辑分明，托福阅读中使用到的学术类文章尤其如此，在阅读中如果没有准确把握信息之间的关联无论对于我们文章的理解还是解题都非常不利。

　　阅读中常见的逻辑关系主要有并列、转折、因果、总分（举例）、比较和条件，我们可以利用逻辑连接词或者暗含逻辑关系的动词（语意）来识别和理解，对于解题也会有所裨益，先来看一个高频题型——词汇题是如何利用逻辑（上下文）帮助我们猜测单词的意思的Paragraph 5: There is little doubt, however, that desertification in most areas results primarily from human activities rather than natural processes. The semiarid lands bordering the deserts exist in a delicate ecological balance and are limited in their potential to adjust to increased environmental pressures. Expanding populations are subjecting the land to increasing pressures to provide them with food and fuel. In wet periods, the land may be able to respond to these stresses.During the dry periods that are common phenomena along the desert margins, though, the pressure on the land is often far in excess of its diminished capacity, and desertification results.The word delicate in the passage is closest in meaning to

　　A.Fragile

　　B.Predictable

　　C.Complex

　　D.Valuable

　　上面这个题（TPO 2 Desert Formation）考查了文中“delicate”这个单词的意思，对不少处于备考初期同学来说是比较陌生的词汇，不过我们不难发现在原文中“exist in a delicate ecological balance”和“are limited in their potential”存在并列关系，这两部分信息语意相关且方向一致，通过“limited”（受限）这个负向的表达就不难看出正确选项为 A.fragile（脆弱的）。

　　再如 ETS 托福阅读样题《Opportunists and Competitors》中的一道词汇题：

　　Paragraph 1: Growth, reproduction, and daily metabolism all require an organismto expend energy. The expenditure of energy is essentially a process of budgeting,just as finances are budgeted. If all of one's money is spent on clothes, theremay be none left to buy food or go to the movies. Similarly, a plant or animalcannot squander all its energy on growing a big body if none would be left over for reproduction, for this is the surest way to extinction. he word squander in the passage is closest in meaning to

　　A.extend

　　B.transform

　　C.activate

　　D.waste

　　这道题考查“squander”一词，相对于四个选项较为生僻，我们回到文中，观察该词周围的信息，发现逻辑词“similarly”（类似地），表达了类比的逻辑关系，说明“squander”这个单词所在句和上一句话语意相关，找到和该词的对应表达“spent”之后就不难判断答案为 D.waste（浪费）了。

　　前面主要讲到了逻辑关系在词汇题中的使用，接下来以托福阅读基本题型之一的句子简化题为例再看一下逻辑的重要性，比如 TPO 1《 Timberline Vegetation on Mountains》：

　　The Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes.

　　A.Because of their deformed shapes at high altitudes, trees are not likely to be seriously harmed by the strong winds typical of those altitudes.

　　B.As altitude increases, the velocity of winds increase, leading to a serious decrease in the number of trees found at high altitudes

　　C.The deformed shapes of trees at high altitudes show that wind velocity, which increase with altitude, can cause serious hardship for trees.

　　D.Increased wind velocity at high altitudes deforms the shapes of trees, and this may cause serious stress for trees.

　　选项 D 错误之处就在于因果逻辑关系颠倒，很多同学会误选它，但是如果我们精读原句的时候关注到“as is made evident by”（=as is shown by）表示“由……表明”，是因果逻辑的体现（前因后果），就较容易排除 D 选项了，而 C 选项才是正确传达原句主要信息并且逻辑

　　正确的选项。

　　再比如 TPO 21 《The Origins of Agriculture》中的句子简化题：The temperature increased dramatically in a short period of time (years rather than centuries), allowing for a growth of the hunting-gathering population due to the abundance of resources.

　　A.The resources needed by the growing hunting and gathering population increased rapidly once temperatures rose.

　　B.Dramatic temperature increases and the simultaneous growth of the hunting andgathering population led to the need for more resources.

　　C.Higher temperatures led to the existence of increased resources, thus enabling the hunting and gathering population to grow.

　　D.The dramatic temperature increase occurred during the few years when abundant resources allowed the hunting and gathering population to grow.

　　这题易错选项 D 也是逻辑上的错误，原句通过“allow for”和“due to”传达了双重因果逻辑关系，即温度上升使得资源丰富所以人口增加，而 D 选项虽然原句主要信息都包含但是因为缺失了温度上升和资源丰富之间的因果逻辑关系所以不如 C 选项和原句更为贴合。

　　通过以上几题我们主要利用文中出现的句中、句间重要的逻辑关系来帮助解决句子简化题和词汇题，其实在诸多题型中都有逻辑关系这个考点，其他较为典型的题目如句子插入题、修辞目的题等。另外对于逻辑关系的准确识别也可以帮助我们梳理各个信息点之间的联系，对于微观层次的句子（句内逻辑关系）、到宏观层次的段落（句间逻辑关系）及篇章（段落与段落之间的逻辑关系），在这个过程中不仅我们的逻辑思维能力会得到很大的提升和改善，并且大家一定会对各个题型及考点有更为清楚的认知，对于总结的解题方法和技巧也不再只是生搬硬套而是做到融会贯通，当我们把阅读能力和解题方法能够融合起来时，那么无论是阅读能力还是考试分数都会有长足的进步，高能且高分。

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