阅读题，重在理解，一是靠学生的基础知识积累，二是学生对于出题的正确的逻辑分析。在这中间，同义替换的现象频频发生。这个内容在留预四级教材unit 7 reading 2的close reading部分有简短的讲解。借此，基于留预教材，来梳理6种不同类型的同义替换，帮助大家在大英四六级钟斩获高分。
There are a number of different factors that lead to the extinction or near extinction of an animal. One reason, especially in the past, was the over-hunting of an animal.（四级unit 7 reading 2）
这个句子中的factors对应的同义词就是reason。再来看留预教材中的阅读出题，四级unit 7 reading 2 close reading 3-6：
Giving whales a protected status may lower_________ and reduce global warming.
Protecting whale populations could rebalance the ecosystem in our oceans and help reduce carbon levels in the atmosphere.
42.Recycling used products can help manufacturers reduce production costs.（2019年6月卷2）
N These examples are just the tip of the iceberg, but they demonstrate how helping customers get more use of their materials can transform value chains and operations. Reducing waste by incorporating used materials into production can cut costs and decrease the price of procurement (采购): less to be procured from the outside and more to be re-utilized from the inside.
这里的例子出现在信息匹配题。四级unit 5 reading 2 Global reading 中的k选项：
题干：k water problems resulting from climate change
原文：6 As sea temperatures rise, cold-water species of fish and sea animals are dying out. Diseases are spreading more rapidly, damaging coral reefs and marine life, especially shellfish.
题干出现的是water problem，原文出现的是cold-water species of fish，sea animals，coral reefs，marine life，shellfish等，这些都是属于水里面的生物，这些都与水有关。这里属于上下义关系。
43.It has been found that not eating breakfast is related to the incidence of certain diseases in some countries.（2019年12月卷2）
G Researchers from the University of Surrey and University of Aberdeen are halfway through research looking into the mechanisms behind how the time we eat influences body weight. Early findings suggest that a bigger breakfast is beneficial to weight control. Breakfast has been found to affect more than just weight. Skipping breakfast has been associated with a 27% increased risk of heart disease, a 21% higher risk of type 2 diabetes in men, and a 20% higher risk of type 2 diabetes in women. One reason may be breakfast’s nutritional value--partly because cereal is fortified with vitamins. In one study on the breakfast habits of l,600 young people in the UK. researchers found that the fibre and micronutrient intake was better in those who had breakfast regularly. There have been similar findings in Australia, Brazil, Canada and the US.
题目出现的是certain diseases，对应出现的是heart，disease和diabetes；以及题干的国家in some countries, 对应原文出现的是Australia, Brazil, Canada and the US。这是属于上义词对应的下义词。
词性改变的同义替换相对而言简单一些，主要考察学生的耐心以及能否识别出相关的前后缀，根据单词相同的词根来确定这里说的是同一个意思。如：四级unit 2：Jin Su broke the cup when she dropped it. However, she was able to repair break, and so could still use the broken cup.
这其中还包括主动变被动，句子顺序调整等情况。如：unit 7 reading 1 global reading：
题干：C What is lost when a language dies?
原文：Some argue that losing a language is to lose more than simply its words, grammar, and pronunciation. With it, we lose cultural knowledge and identity.
CET 6 真题应用
38.Adequate rest not only helps one recover, but also increases one’s work efficiency. （2018年12月卷3）
[L]In addition, you can take a cognitive break every 90 minutes to charge your batteries. Try to not have lunch at your desk, but instead spend time outside or with your friends—not talking about work. Take all of your paid time off, which not only gives you recovery periods, but raises your productivity and likelihood of promotion.
代词指代在理解上下文的意思上会造成一定的障碍，常见代词it，that，this，they等都有可能造成学生对上下文造成误解。四级unit 1 reading 2 close reading就专门考查了学生对于other，others，the other，the others，another这几个单词在原文中的指代作用，但是代词的指代一般指代的是名词结构。除了代词之外，还有be动词，助动词，情态动词的省略用法，替换原文出现的动词。如：Unit 3 reading 1 close reading 选择划线部分的省略词代指的内容：
题干: 1. Our bodies grow and develop as we age, so it should come as no surprise that our thoughts do too--that is, the very way in which we think,
选项：a. Age b. think c. grow and develop
这里的目标词是do，根据句子意思这里的答案应该是c。此处的指代便是属于使用助动词do避免上下文之间重复动词结构吧，那同样，除了do，还有does，did，have，has，had以及be动词的各种形式。课本P48还提供了so, too, neither, the former, the latter.
46.What do we learn about Knowledge-Based Artificial Intelligence? (2019年12月卷1)
A)It is a robot that can answer students’ questions
B)It is a course designed for students to learn online
C)It is a high-tech device that revolutionizes teaching
D)It is a computer program that aids student learning
Professor Ashok Goel of Georgia Tech developed an artificially intelligent teaching assistant to help handle the enormous number of student questions in the online class, Knowledge-Based Artificial Intelligence. This online course is a core requirement of Georgia Tech's online Master of Science in Computer Science program. Professor Goel already had eight teaching assistants, but that wasn’t enough to deal with the overwhelming number of daily questions from students.
在上课过程中，发现这类选择题学生有时候会忽略选项中it，they等单词的指代作用，这个题目就是明显的需要区分题干it代指Knowledge-Based Artificial Intelligence，并且需要定位到原文的Knowledge-Based Artificial Intelligence后面这句中的this online course所以可以判断这个目标词汇一定十个凑色。答案选择B。
同义解释与同义词并不一样，同义词是词对词，而同义解释是词对词组，短语甚至是句子。在英语阅读中，这类的同义替换的类型占了很大一部分，因为它的替换方式很灵活，形式很多样，所以总结起来属于没有很好的规律的一条。如：unit 7 reading 2 Close reading 3 填空题
题干：1. One way to conserve a species is to stop hunting of the rest of the_______.
原文：Protecting the wider food chain can help increase the population of an endangered species.
此处的答案是food chain，题干中的修饰词是the rest of，原文使用的是wider，这里的同义解释相对而言比较抽象。但是仔细理解不难发现，其实这种同义替换还是挺有难度。另外，本题中第四小题：
题干：4. Humans rely on local environment for access to ____ and ______.
原文：People depend on the ecosystem to ensure the supply of food and water.
对比之下，发现这个题出现了同义词的同义替换：题干的rely on 和原文的depend on，另外题干的for access to其实就是原文中的ensure the supply of。这两个题目对于该部分的对比是比较明显的，可以说明同义词和同义解释之间的区别。
39.With telemedicine, patients in regions short of professional medical service are able to receive better medical care.
B Doctors are linking up with patients by phone, email and webcam（网络摄像头）. They're also consulting with each other electronically-sometimes to make split-second decisions on heart attacks and strokes. Patients, meanwhile, are using new devices to relay their blood pressure, heart rate and other vital signs to their doctors so they can manage chronic conditions at home. Telemedicine also allows for better care in places where medical expertise is hard to come by. Five to 10 times a day, Doctors Without Borders relays questions about tough cases from its physicians in Niger, South Sudan
and elsewhere to its network of 280 experts around the world, and back again via the internet.
这一句里面的对应很明显是调整了句子的结构，但是其关键词的对应还是其心可昭的，short of对应的hard to come by就很明显是相互解释。
这个部分主要涉及到的应该是一些带有否定词的（not，no等）和不带否定词的否定表达之间的替换。不带否定词的否定表达常见的有：hardly/seldom/barely/never，too...to, few, neither等。这些出现在考题中就需要识别出其中的否定关系，另外，双重否定变肯定的表达也是考点之一。如：unit 8 reading 1 close reading 第二题填空题：
题干：1. ______ and not keeping a promise are often not against the law, but people usually think they are unethical.
原文：Many legal things are often considered unethical. If someone told a serious lie but it was legal, many people would think of it as unethical. If someone broke a promise another person was strongly depending on, many would argue this was unethical.
首先，这里的答案是Lying，是总结第 一个if条件句得出的答案，整个答案的定位需要读懂and并列之后的not keeping a promise，而在原文，并不是带有not 的否定句，而是broke a promise，这两个之间属于带否定词和不带否定词之间的同义替换。另外：unit 8 reading 2 close reading summary填空题中也出现了类似的情况：
题干：A big proportion of unethical behavior happens at work. This is likely to always happen, but companies can use different measures to limit it.
原文：While it is unlikely that unethical behavior can ever be removed from the workplace, there are measures that can be put into place to encourage a more ethical working environment.
此处题干使用的is likely to always happen，对应原文使用的否定形式is unlikely that unethical behavior can ever be removed，并且答案句中的encourage a more ethical working environment和题干的limit it（it代指unethical behavior）也形成了否定和肯定之间的替换。
38 The author emphasizes being anumeric does not affect one’s cognitive abilities. Ri
[E]It is worth stressing that these anumeric people are cognitively (在认知方面) normal, well-adapted to the surroundings they have dominated for centuries. As a child, I spent some time living with anumeric people, the Piraha who live along the banks of the black Maici River. Like other outsiders, I was continually impressed by their superior understanding of the ecology we shared. Yet numberless people struggle with tasks that require precise discrimination between quantities. Perhaps this should be unsurprising. After all, without counting, how can someone tell whether there are, say,seven or eight coconuts(椰子)in a tree? Such seemingly straightforward distinctions become blurry through numberless eyes.
这个例子中题干出现的是does not affect属于否定，但是在原文对应到的关键词是are cognitively normal，所以整体上否定对应的是肯定的表达，这个部分的匹配还是有难度的。