总会有些题目的否定表达让我们感觉不太习惯，比如多重否定表达。直接理解有困难怎么办? 我们可以使用对立二分法进行对立概念的转化。
在一对对立二分的概念A和B中，我们对其中一个概念的肯定就是对另一个概念的否定，反之，对其中一个概念的否定就是对另一个概念的肯定。
例如：有人说，
翘课是一种光荣。
他就等于在说，翘课不是一种耻辱。
如果他说，翘课不是一种耻辱。
他就等于在说，翘课是一种光荣。
使用对立二分法，我们可以把否定表达转化为肯定表达，把双重否定表达转化为肯定表达，以便于理解题义。
例如：
62.5. She was criticized by her fellow lawyers not because she was not _____, but because she so _____ prepared her cases that she failed to bring the expected number to trial.
(A) well versed…knowledgeable
(B) well trained…enthusiastically
(C) congenial…rapidly
(D) hardworking…minutely
(E) astute…efficiently
分析：
显然，这是一个 not A, but B 结构。A B 分别是可以被同事批评的原因，都应该是负评价。A 中 有个not, 1空应该是正评价。可惜几个选项都是正评，解题价值不大。
B中有一个 so C that D 因果结构，D是未能达到期待的数量，C是造成数量不够的原因。选项中，只有D 事无巨细地 符合要求。
61.7. Although the meanings of words may necessarily be liable to change, it does not follow that the lexicographer is therefore unable to render spelling , in a GREat measure, .
(A) arbitrary
(B) superfluous
(C) interesting
(D) flexible
(E) constant
分析：
前后句是转折关系，后句是一个双重否定表达，转化成肯定表达就是：
it does follow that the lexicographer is therefore able to render spelling , in a GREat measure, .
空格选 liable to change 的反义词即可。
67.4. While admitting that the risks incurred by use of the insecticide were not _____, the manufacture’s spokesperson argued that effective _____ were simply not available.
(A) inconsequential…substitutes
(B) unusual…alternatives
(C) increasing…procedures
(D) indeterminable…safeguards
(E) proven…antidotes
分析：
前句中的not 表达让人感觉别扭，可以转化为对立概念的肯定表达。整体上，发言人承认的危险应该是严重的。有了not, 1空是不严重的/轻微的，这样，负负得正，整体上构成严重的。只有A 符合。
51.7. Marshall’s confrontational style could alienate almost anyone: he even antagonized a board of directors that included a number of his supporters and that had a reputation for not being easily _____.
(A) intimidated
(B) mollified
(C) reconciled
(D) provoked
(E) motivated
分析：
空格处于that 定语从句中，该定语从句与前面that定语从句并列修饰a board of directors.
前that 从句说委员会是支持他的，后that 从句整体上也应该是正评价的。如果没有not, 空格应该是安抚的同义词。B C 符合。有了not, 空格应为激怒的同义词。D 符合。
另外，从全句整体结构上，空格应为 alienate, antagonize 的同义词。
57.1. Since most if not all learning occurs through _____, relating one observation to another, it would be strange indeed if the study of other cultures did not also illuminate the study of our own.
(A) assumptions
(B) experiments
(C) comparisons
(D) repetitions
(E) impressions
分析：
后句是一个双重否定表达，变成肯定句式可能理解更便利。
it would be normal indeed if the study of other cultures did illuminate the study of our own.
其实，以上所用的肯定否定转化并不准确。对对立概念中一个的否定并不必然是对另一个的肯定。否定的表达通常比直接肯定的表达拥有更大的灵活空间。比如：
You are good when you strive to give of yourself.
Yet you are not evil when you seek gain for yourself.
by Kahlil Gibran 纪伯伦
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