83、 Many population studies have linked a high-salt diet to high rates of hypertension and shown that in societies where they consume little salt, their blood pressure typically does not rise with age.
　　(A) shown that in societies where they consume little salt, their
　　(B) shown that in societies that have consumed little salt, their
　　(C) shown that in societies where little salt is consumed,
　　(D) they showed that in societies where little salt is consumed,
　　(E) they showed that in societies where they consume little salt, their
　　原文意思：研究显示出饮食中含盐比较多和 hypertension 有关系，研究还显示出在一些吃 盐比较少的地方，高血压不会随着年龄的增加而增加。
　　题目分析：原文有一个并列关系，就是研究显示。 。 。研究还显示。 。 。 ，D 和 E 加的那个 THEY 没必要， 因为发起者都是研究， 没有变， 加 THEY 画蛇添足， ABC 中 AB 都用 THEIR， 但是 THEIR 指谁呢？根据语义这个 THEIR 应该指这些人，但是前面没有提到人，只有 POPULATION STUDIES，所以 THEIR 加上没有指代的东西，选 C。