下面，我们通过一些GRE填空高频题目理解双研究对象的关系。

例如最近的高频考题：

“两个研究对象取同”

Proponents of international regulation of environmental issues have always struggled against scientific uncertainty and economic hostility, two obstacles which, from a political standpoint, often have been closely related, as economic hostility toward environmental regulation for economic reasons have (i)_____ the considerable uncertainty underlying most environmental challenges to (ii)_____ of environmental regulation.

句中两个研究对象：“scientificuncertainty” 以及“economichostility”。这两个obstacles紧密相关取同，因此排除AB。

由于两个障碍对internationalregulation of environmental issues有负向作用，所以选E最合适。exploit利用，downplaythe legitimacy 对合法性轻描淡写。

“两个研究对象取反”

Conventional deposits of oil and gas are actually the final resting place of far-traveled hydrocarbons that were (i)_____ deeper source beds of organic-rich rock. By contrast, shale gas (ii)_____ its birthplace, remaining in the source bed whose organic matter produced the gas.

两个研究对象：“Conventionaldeposits of oil and gas ”以及“shalegas”

通过by contrast 可知两者特征相反，前者的特征是far-traveled，所以第一空选B，后者的特征是remaining，所以第二空选D选项。generate产生，neverleave 从来不离开。

“两个研究对象取反”

Inuit print making is less (i)_____ than carving in that it does not have substantial historical precedents, although there are (ii)_____ incised carvings on bone or antler, facial tattoo marks or inlay skin work on clothing, mitts and footwear. Carving materials such as stone, bone, antler, wood, and  ivory were (iii)_____, but paper and drawing tools were unknown until introduced by early explorers and missionaries.

两个研究对象：Inuitprint making以及carving，两者特征取反。

in that it does not have substantial historical precedents中的it指的是Inuitprint making，既然没有先例，说明Inuitprint making 比起carving不是那么传统，第一空选A选项；

第二空让步，前面说两者不同，但是两者还是有某种联系，第二空选D选项，第三空根据but前后对比，paperand drawing tools were unknown until introduced by early explorersand missionaries 说明carvingmaterials 是取unknown的反义，所以第三空选G选项。

traditional传统的，affinity紧密联系，availabilitylocally 当地能获得。注意此题的affinity不要理解成“喜爱”这层意思。