在英语学习中我们不难发现，一篇好的文章用词丰富、句式多变。
雅思阅读的文章均摘自西方报刊杂志，属于原汁原味的外文资料，自然也会遵循着以上规律，所以阅读中对词汇的考查万变不离其宗，无非是对同义词、反义词、同根词进行考核。
首先我们来给同(反)义词下个定义：释义相同(反)的词。如： “attraction” 和 “allure”虽然词性不同但我们仍然称它们为同义词。同样， “essentially” 和 “unnecessary” 称为反义词。同根词指的是一个单词的所有词性的组合, 如: value, valuable, invaluable, valueless. 可见这里的定义是泛泛的，是为了很好的考试而进行的 “粗糙却很受用” 定义。
了解了词汇的考核形式，下面笔者就雅思阅读中典型的词汇换用举几个例子：
例一：
原文：In Europe, the obstacle has been conservative local authorities and developers who prefer to ensure quick sales with conventional mass-produced housing.
题目：Many developers prefer mass-produced houses because they...
答案：sell quickly
解析：原文和题目中的句意关键词developer, prefer 均相同，但 “housing” 换成了 “houses”, 即同根词的代换。 “they” 指代 “houses”， 又因为 “because” 应该引导从句，所以答案为动词短语。 “quick sales” 对应的动词短语为上述答案， 也就是说答案也是根据同根词替换而来的。
例二：
原文：While this includes complex kingdoms, as in Africa, and ancient empires, such as those of the Americas, the primary focus of attention in the twentieth century has been on small-scale societies.
题目：The twentieth-century collections come mainly from mainstream societies such as the US and Europe.
答案：FALSE
解析：原文与题目对比出现了一组反义代换词 “small-scale societies” 和 “mainstream societies”.
例三：
原文：Countries all over the world are actively promoting their wilderness regions to high-spending tourists. The attraction of these regions is obvious: by definition, wilderness tourism requires litter or no initial investment.
题目：The low cost of setting wilderness tourism makes it attractive to many countries.
答案：TRUE
解析：low cost=little or no initial investment; “attractive” 为 “attraction”的同根词代换。
例四：
原文：In their new location, the beekeeper will pay the farmer to allow his bees to feed in such places as orange groves.
题目： They transport their hives to orange groves where farmers (charge) beekeepers for placing them on their land. Here the bees make honey.
解析：这是剑桥上的一个填空题。不难看出，为了考查词汇，题目对原文进行了同义句转换，但是对主语和宾语进行了调换，所以谓语动词也采用了相应的反义词形式。
由以上示例不难看出，我们在背雅思考试词汇时应注意着重记忆形容词、动词。 对每个雅思必备词汇的同根词要加以关注。并且可以从大家背单词时容易永远都没有背到就已经放弃了的词汇入手，如按“M, N, O, P , I, T…”顺序，重点记忆动词、形容词。再记忆经常被我们光顾的 “A, B, C, D 或X, Y, Z”, 你会发现效果很棒的!!!
总之，学习也是一种挑战，“知已知彼”，了解考什么才能 “百战不殆”，知道怎么应考。祝愿“烤鸭们”能够找到单词记忆办法的同时，“有的放矢”记单词。