同义替换可以说是雅思阅读必不可少的考查方式，派生词替换、同义词或同义词词组以及反义词的否定形式是大多数人比较熟悉的，但上义词替换下义词却是很多同学的死穴。深圳新航道小编介绍，上义词与下义词是一组相对概念，范围大的词汇为上义词，而其下属的具体例子为其下义词。比如，学科subject和化学chemistry就是一对上义词和下义词。

上义词与下义词的概念弄明白后，还要熟悉雅思阅读考查这类替换的方式，简而言之，就是‘题上文下’，也就是说上义词会出现在题干中替换原文中的下义词，如果在雅思备考期间能很好的掌握这部分知识，那么对于阅读分数的提升相信有不错的效果。

命题人是根据原文中的具体信息来命题的，用范围较大的上义词subject来替换原文中更为具体的chemistry就顺理成章了。

判断题：

Bakelite was only available in a limited range of colours.

原文：

Baekeland's invention， although treated with disdain in its early years， went on to enjoy an unparalleled popularity which lasted throughout the first half of the twentieth century. It became the wonder product of the new world of industrial expansion - 'the material of a thousand uses，. Being both non-porous and heat-resistant， Bakelite kitchen goods were promoted as being germ-free and sterilisable. Electrical manufacturers seized on its insulating properties， and consumers everywhere relished its dazzling array of shades， delighted that they were now， at last， no longer restricted to the wood tones and drab browns of the pre-plastic era. It then fell from favour again during the 1950s， and was despised and destroyed in vast quantities. Recently， however， it has been experiencing something of a renaissance， with renewed demand for original Bakelite objects in the collectors' marketplace， and museums， societies and dedicated individuals once again appreciating the style and originality of this innovative material.

实际上，此题就运用了上义词替换下义词，可以通过colours 定位到原文‘ no longer restricted to the wood tones and drab browns of the pre-plastic era’。

也就是将colours替换了browns。由于看出limit与restrict的替换难度并不大，那么此题与原文中no longer矛盾，选FALSE也就很轻松了。