下面剖析英語六級閱讀真題長難句(4)，希望考生在練習同時思考長難句的句子結構。
　　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. 閱讀. 12. Text 1)
　　【譯文】在某種程度上，盡管研究者們仍在努力研究意圖發現維他命所起效果的真相，但是維他命對人體可能有的益處物超所值這種說法是有道理的。
　　【析句】復合句。主句it makes sense to say, 后面是省略了that的賓語從句the potential benefit outweighs the cost.主句前，while引導讓步狀語從句，figuring out后where the truth lies作賓語從句。
　　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. 閱讀. 12. Text 1)
　　【譯文】維他命已被證明能夠減少胚胎的缺陷，并且最新試驗證明葉酸和維生素B12以及B16的一種一起服用也能降低手術修復后動脈血管堵塞的可能性。
　　【析句】主句由and連接兩個并列句，首先是It's been proved to limit the number of defects in embryos, it作形式主語，真正的主語是后面的不定式結構，然后是a recent trial found+賓語從句that folate in combination with...decreases the re-blockage of..., 注意in combination with用在句子中，謂語動詞的單復數看前面的名詞。
　　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. 閱讀. 12. Text 3)
　　【譯文】關于人性是由什么組成的，人們眾說紛紜，但是人們一致同意，人性中存在著某種本質，正是這種本質特性是人之所以為人的原因。
　　【析句】主句由but連接的兩個成轉折關系的并列句構成。前句是There were various views about+賓語從句，簡單句。后句主句there was agreement, that such an essence exists，that there is something同作agreement的同位語從句，兩個并列的同位語從句間，that is to say作插入語。by virtue of which man is man在后一同位語從句中作定語從句修飾something.