在托福阅读中，很多同学们经常看漏或者理解偏差文本中的否定逻辑关系。本文将详细讲解托福阅读中常见的否定逻辑关系，并通过实际例题分析如何高效利用否定逻辑。
一、托福阅读常见否定逻辑关系词
我们先来看看在托福阅读中，会有哪些词提示我们这里有否定关系呢？
首先，非常明显的有：
no, not, never, nor, none neither
除此之外，还有：
hardly, scarcely, rarely
little,fail to, refuse, remove, deny,avoid, miss, reject,absence of, lack of,too…to
否定前缀：
a-, ab-, dis-, il-, im-, in-, non- , un- ,mis-, dis-/ de-, contra-, anti-, -less
另外，有些句子中还会出现双重否定，表示肯定。比如not fail to。
我们需要特别注意这些单词/词组，避免对原文信息进行错误理解。
二、托福否定关系的实际应用
托福词汇题
否定前缀是词汇题中经常出的一个考点，把握否定前缀可以帮助我们推测一些生词，依靠否定前缀对选项进行一个排除。
Therefore, when Europeans carrying these diseases inadvertently spread them among American peoples, sickness spread rapidly, resulting in many deaths.
The word "inadvertently" in the passage is closest in meaning to
A without intention
B for the first time
C one after another
D suddenly
原句中的"inadvertently"由否定前缀"in-"（非）和"advertently"（故意地）构成，字面意为"非故意地"。通过否定前缀可快速排除B（首次）、C（连续）和D（突然），锁定A选项（无意的）。正确答案为A。
托福句子简化题
He refused to develop projection technology, reasoning that if he made and sold projectors, then exhibitors would purchase only one machine-a projector-from him instead of several.
Which of the sentences below best expresses the essential information in the highlighted sentence from the passage?Incorrect answer choices change the meaning in important ways or leave out essential information.
A.Edison was more interested in developing a variety of machines than in developing a technology based on only one.
B.Edison refused to work on projection technology because he did not think exhibitors would replace their projectors with newer machines.
C.Edison did not want to develop projection technology because it limited the number of machines he could sell.
D.Edison would not develop projection technology unless exhibitors agreed to purchase more than one projector from him.
原句的否定逻辑体现在"refused to"和"instead of"：
正确选项C中，did not want to 是对refused to的同义转写，limited the number对应only one ...instead of several.而A选项说more interested in developing a variety of machines跟原文表达矛盾，B中的"replace"曲解原意，D错误添加条件关系。
托福否定事实信息题
How might this inability to recall early experiences be explained? ①The sheer passage of time does not account for it; adults have excellent recognition of pictures of people who attended high school with them 35 years earlier. //②Another seemingly plausible explanation-that infants do not form enduring memories at this point in development-also is incorrect. Children two and a half to three years old remember experiences that occurred in their first year, and eleven month olds remember some events a year later. //③Nor does the hypothesis that infantile amnesia reflects repression-or holding back-of sexually charged episodes explain the phenomenon. While such repression may occur, people cannot remember ordinary events from the infant and toddler periods either.
All of the following theories about the inability to recall early experiences are rejected in paragraph 2 EXCEPT:
A.The ability to recall an event decreases as the time after the event increases.
B.Young children are not capable of forming memories that last for more than a short time.
C.People may hold back sexually meaningful memories.
D.Most events in childhood are too ordinary to be worth remembering.
根据题干设问，我们需要找出未被否定的理论。原文逐个列举了3种解释并一一否定。
其中A对应第一种理论"sheer passage of time does not account";B对应第二种理论Another seemingly plausible explanation-that infants do not form enduring memories at this point in development-also is incorrect。
C对应第三种理论Nor does the hypothesis that infantile amnesia reflects repression-or holding back-of sexually charged episodes explain the phenomenon。
所以答案选D。原文只是说 people cannot remember ordinary events，并没有说这些事情太普通而不值得回忆。
托福事实信息题
The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.
Where is the lower timberline mentioned in paragraph 1 likely to be found?
A.In an area that has little water
B.In an area that has little sunlight
C.Above a transition area
D.On a mountain that has on upper timberline.
原文否定逻辑："usually because of a lack of moisture"直接对应选项A中"little water"。B阳光不足在原文未提及，CD选项表述的位置错误，是upper timberline的情况而不是题目问到的lower timberline。
托福句子插入题
■Watt's steam engine soon showed what it could do. ■It liberated industry from dependence on running water. ■The engine eliminated water in the mines by driving efficient pumps, which made possible deeper and deeper mining. ■The ready availability of coal inspired William Murdoch during the 1790s to develop the first new form of nighttime illumination to be discovered in a millennium and a half. Coal gas rivaled smoky oil lamps and flickering candles, and early in the new century, well-to-do Londoners "grew accustomed to" gaslit houses and even streets. Iron manufacturers, which had starved for fuel while depending on charcoal, also benefited from ever-increasing supplies of coal: blast furnaces with steam-powered bellows turned out more iron and steel for the new machinery. Steam became the motive force of the Industrial Revolution as coal and iron ore were the raw materials.
Look at the four squares ■ that indicate where the following sentence could be added to the passage.Where would the sentence best fit?
The factories did not have to go to the streams when power could come to the factories．
Where would be the sentence best fit? Click on a square to add the sentence to the passage.
A.
B.
C.
D.
插入句中The factories did not have to go to the streams 对应 liberated industry from dependence on running water，但是第二句话it指代前文Watt's steam engine。所以插入句放到C更合适。
三、总结
可以看出，否定逻辑是托福阅读中理解多个观点或信息的重要解题线索。掌握这些常见的否定逻辑关系词并理解它们在不同题型中的运用，将帮助我们更好地把握文章脉络，快速定位信息，从而提高解题的准确性和效率。希望考生在备考过程中多加练习，提高对否定关系的敏感度。
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