旧PREP sc2 61与101矛盾解释，恳请帮忙

61.   (27648-!-item-!-188;#058&003611)

Researchers in Germany have unearthed 400,000-year-old wooden spears from what it appears was an ancient lakeshore hunting ground as stunning evidence of human ancestors who systematically hunted big game much earlier than believed.

(A) it appears was an ancient lakeshore hunting ground as stunning evidence of human ancestors who

(B) it appears had been an ancient lakeshore hunting ground and is stunning evidence that human ancestors

(C) it appears to have been an ancient lakeshore hunting ground and is stunning evidence that human ancestors

(D) appears to be an ancient lakeshore hunting ground, stunning evidence that human ancestors    答案：D

(E) appears that it is an ancient lakeshore hunting ground, stunning evidence of human ancestors who

语法注释在否定ABC时都说了这样一句，What从句中出现what和it两个主语，以及appears和was两个谓语，句子结构错误。但是101的选项却与之矛盾。

The electronics company has unveiled what it claims to be the world's smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs less than 11 ounces.

(A) to be the world's smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs

(B) to be the smallest network digital camcorder in the world, which is as long as a handheld computer, weighing

(C) is the smallest network digital camcorder in the world, which is as long as a handheld computer, and it weighs

(D) is the world's smallest network digital camcorder, which is as long as a handheld computer and weighs   答案：D

(E) is the world's smallest network digital camcorder, the length of which is that of a handheld computer, weighing

我们看到D明显的出现了两个主语what 和it， 两个谓语is 和claims。为什么这个就不算错呢？

请NN指教！！

呵呵，这两道题很好啊！

101中的it claims 是插入语，你把它省掉剩下的结构是完整的

61中的则不是插入语。

lz看到这肯定气坏了，而且肯定想问那什么时候那个成分可以做插入，什么时候不可以呢？

一般it如果和what指代的不是同一对象，就是插入语（101中的it指代的是company，而what指代的是company发现的东西），如果是同一对象，那肯定不是插入语（61中的it和what都指代的是hunting ground）。如果不是插入语，那么原句就有了两个主语，redundant，要省掉it。

听上去有道理啊，谢楼上的了。