奇怪！Prep 61和prep 101为什么相同的结构一个算错一个算对呢？

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 stunning evidence that human ancestors

C. appears was 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

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

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.
                    ×prep关于错误原因是这样解释的：因为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

PREP 101. 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

E.      is the world’s smallest network digital camcorder, the length of which is that of a handheld computer, weighing

The electronics company has unveiled what it claims is the world’s smallest network digital camcorder, which is as long as a handheld computer and weighs less than 11 ounces.√ 为什么同样的结构这里就是对的呢？麻烦NN指点一下，谢谢！

第一题关键是appear to 固定搭配，第二个是一个以what it claims引导的主语，接谓语is和weighs.即what it claims...is,what it claims...weighs

谢谢楼上的，我对平行没有疑问啦，是需要“Prep 61和prep 101为什么相同的结构一个算错一个算对呢？”的一个更好的解释！

The electronics company has unveiled what it claims is the world’s smallest network digital camcorder, which is as long as a handheld computer and weighs less than 11 ounces.√ 说明黄色部分是对的。可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.
                × prep却说绿色部分结构是错的！为什么呢？

AlienX解释得精辟~~顶一个~

既然在说what从句，我还有一个问题，关于什么时候使用what从句。

17.The success of the program to eradicate smallpox has stimulated experts to pursue what they had not previously considered possible--better control, if not eradication, of the other infections such as measles and yaws.

(A) what they had not previously considered possible--better control, if not eradication, of the other infections such as

(B) what they had not previously considered a possibility--better control, if not eradication, of such infections like

(C) something they had not previously considered possible-better control, if not eradication, of such infections as

(D) something not considered a previous possibility--better control and perhaps eradication, of other infections such as

(E) the possibility of what they had not previously considered--better control and possibly eradication of infections like

如果C中something改成what，这个句子有没有什么问题呢？什么情况下使用what从句呢？