请教prep里的两道题，谢谢啦

jessegxy

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

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

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

想请教一下这是不是有关主语从句·的知识点，对这两题比较迷惑，请教大牛，能否通过这两题讲解一下红字部分的有关知识点啊，谢啦

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

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

想请教一下这是不是有关主语从句·的知识点，对这两题比较迷惑，请教大牛，能否通过这两题讲解一下红字部分的有关知识点啊，谢啦