GRE是一个选拔性考试，ETS的职责是帮助大学研究生院把适合学术研究的、推理能力强的人才选拔出来。这一点就决定了GRE填空的同义重复和反义重复不能过于直白，也就是说，ETS必然要在遵守规则的前提下寻求变化。
ETS所寻求的变化，在反义重复方面变化空间并不大，无非是把词汇变得难一些，因为对立二分的概念还是很容易分辨的。在同义重复方面，ETS的变化空间就要大得多，因为同样一个意思可以用很多的方式来表达。这就需要我们具有更强一些的语言功底和主动寻找的意识。
举例说明：找出两对同义词。
37.5. Although some consider forcefulness and persistence to be two traits desirable to the same degree, I think that making a violent effort is much less useful than maintaining a steady one.
58.3. Joe spoke of superfluous and vital matters with exactly the same degree of intensity, as though for him serious mattered neither more nor less than did trivialities.
9.2. A perennial goal in zoology is to infer function from structure, relating the behavior of am organism to its physical form and cellular organization.
11.7. When theories formerly considered to be disinterested in their scientific objectivity are found instead to reflect a consistent observational and evaluative bias, then the presumed neutrality of science gives way to the recognition that categories of knowledge are human construction.