下面剖析英语六级阅读真题长难句(4)，希望考生在练习同时思考长难句的句子结构。
　　1. At some point, while researchers work on figuring out where the truth lies, it just makes sense to say the potential benefit outweighs the cost. (2003. 阅读. 12. Text 1)
　　【译文】在某种程度上，尽管研究者们仍在努力研究意图发现维他命所起效果的真相，但是维他命对人体可能有的益处物超所值这种说法是有道理的。
　　【析句】复合句。主句it makes sense to say, 后面是省略了that的宾语从句the potential benefit outweighs the cost.主句前，while引导让步状语从句，figuring out后where the truth lies作宾语从句。
　　2. It’s been proved to limit the number of defects in embryos, and a recent trial found that folate in combination with vitamin B 12 and a form of B6 also decreases the re-blockage of arteries after surgical repair. (2003. 阅读. 12. Text 1)
　　【译文】维他命已被证明能够减少胚胎的缺陷，并且最新试验证明叶酸和维生素B12以及B16的一种一起服用也能降低手术修复后动脉血管堵塞的可能性。
　　【析句】主句由and连接两个并列句，首先是It's been proved to limit the number of defects in embryos, it作形式主语，真正的主语是后面的不定式结构，然后是a recent trial found+宾语从句that folate in combination with...decreases the re-blockage of..., 注意in combination with用在句子中，谓语动词的单复数看前面的名词。
　　3. There were various views about what constitutes it, but there was agreement that such an essence exists—that is to say, that there is something by virtue of which man is man. (2003. 阅读. 12. Text 3)
　　【译文】关于人性是由什么组成的，人们众说纷纭，但是人们一致同意，人性中存在着某种本质，正是这种本质特性是人之所以为人的原因。
　　【析句】主句由but连接的两个成转折关系的并列句构成。前句是There were various views about+宾语从句，简单句。后句主句there was agreement, that such an essence exists，that there is something同作agreement的同位语从句，两个并列的同位语从句间，that is to say作插入语。by virtue of which man is man在后一同位语从句中作定语从句修饰something.