同义替换是阅读必考内容，考查学生是否能准确理解行文含义，准确匹配选项信息与原文考点信息。然而很多同学即使定位正确，仍然会因同义替换而丢分。本文旨在为大家呈现几种常见同义替换考查方式，也是很多同学解题容易出错的地方，以帮助同学们更好地解题。
一．词汇语境含义无法识别
这一类替换主要是指词汇之间本身含义并不相同或接近，但放到语境中，可进行同义替换。比如：
1.It didn’t involve a high degree of apparatuses.
原文：Field leveling was the most basic practice used to optimize the land for farming.
解析: didn’t high degree=the most basic practice
2.Why do some organisms have a resting stage during their life cycle?
原文：It may be advantageous for an organism to have a resistant stage built into the life cycle.
解析：resting stage=resistant stage
3.Animal responses in most situations are predictable.
原文：What is striking about animal behaviors is that they are fixed and seemingly unchangeable.
解析：predictable=regular
二．范围大小易忽视
这类信息一般属于同类别信息，但所指范围大小有区分，因此从事实信息题角度来说不能同义替换。
1. 原文：Electrical stimulation of part of the hypothalamus triggers stereotypical aggressive behaviors in many animals.
A.Artificial stimulation of the hypothalamus results in aggression in animals.
B.Animals behaving aggressively show increased activity in the hypothalamus.
解析：electrical stimulation指电的刺激，而artificial stimulation指人工刺激，这两个概念属于同类别事物，但人工刺激所指范围更广泛一下，不能直接与电刺激同义替换。固B正确。
2.Gliding is used for some animal species as a mean of fleeing from the predators since it enables them to move between trees without the need to descend to the ground and it also is an energy-efficient way to travel long distances between scattered food resources.
误：Because gliding makes them possible to adapt to various forests conditions.
正：Because gliding gives them an advantage of moving through the forest without being exposed to predators in the ground.
解析：fleeing from the predators指躲避猎物，adapt to various forest conditions概念显然更为广泛，所以不能直接同义替换。固选B。
三．过度延伸概念(无中生有）
过度延伸概念属于无中生有，错误选项是对所提及的事物进行过多的理解。
1.Like the pastoralists, Middle Eastern merchants and artisans unhappy with their environment could simply pack up and leave for greener pastures.
错误选项：If they were unhappy in the mercantile environment, they could draw on personal connections to find a different kind of work.
解析：原文并没有提到find a different kind of job属于过度延伸概念。
2.The most significant characteristic of newly formed hamlets were that they were much bigger in terms of size compared to that of the hamlets built before 1300.
错误选项：Population boomed because there were more lands given out to people.
解析：原文在对比大小，并未提及分发土地问题。
四．事物接近但混淆(无中生有）
1.The field preparation enabled marshlands alongside the rivers to be used for husbandry.
错误选项： Field leveling was a technique that allowed farmers to exploit the natural layout of their terrain.
解析：两句话都在讲土地的使用，但原文中并没有提及natural layout布局这个信息。Marshland与natural layout不是指同一事物，无法同义替换。
2.This led to the usage and development of ditches and dikes. Development in drawing the water from the distant locations led number of dams to increase and directed them to wherever they needed them. This was most evident in Yamato Basin where famers built permanent dams. The water detained in the pools was kept for times when they needed water for farming in droughty seasons. Such development led to keen proliferation of crop output as the heated water metabolized the germination of crops and caused crops to mature even faster.
What TWO benefits did the shallow holding pools in the Yamato Basin provide?
(A) A faster harvesting process for the annual yield
(B) An additional source of water
(C) The reduced need of relying on ditches and dikes
(D) A source of heat for the water
解析：B对应原文the water detained...；C项reduce属于否定信息，与原文驳斥；D项对应原文heated water;
A项harvesting process表示收获过程，原文mature even faster表示成熟更快，两个信息都与crop有关，但是这两个信息完全不是一个概念，不能同义替换。