请教几道语法大全上的题

bigmouse

8.A huge flying reptile that died out with the dinosaurs some 65 million years ago, the Quetzalcoatlus had a wingspan of 36 feet, believed to be the largest flying creature the world has ever seen.
(A) believed to be
(B) and that is believed to be
(C) and it is believed to have been
(D) which was, it is believed,
(E) which is believed to be
key:C why not A be right?

11.A letter by Mark Twain, written in the same year as The Adventures of Huckleberry Finn were published, reveals that Twain provided financial assistance to one of the first Black students at Yale Law School.
(A) A letter by Mark Twain, written in the same year as The Adventures of Huckleberry Finn were published,
(B) A letter by Mark Twain, written in the same year of publication as The Adventures of Huckleberry Finn,
(C) A letter by Mark Twain, written in the same year that The Adventures of Huckleberry Finn was published,
(D) Mark Twain wrote a letter in the same year as he published The Adventures of Huckleberry Finn that
(E) Mark Twain wrote a letter in the same year of publication as The Adventures of Huckleberry Finn that
key:C what is difference between "the same....as" and "the same.....that"

12.A little under a million years ago, the briny waters of the Baltic Sea began flooding into the cold North Atlantic: geologists are still debating whether the flood was gradual or created a cataclysm.
(A) whether the flood was gradual or created a cataclysm
(B) if the flood was gradual or created a cataclysm
(C) about whether the flood was gradual or cataclysmic
(D) whether the flood was gradual or cataclysmic
(E) whether the flood was gradual or it created a cataclysm
key why not A be right? what is the difference of these two choice ?

thanks in advance!

miejue

8题 参考http://forum.chasedream.com/dispbbs.asp?boardID=23&ID=21310&star=2

miejue

11题  比较的用法要对称 如果这里用as作比较用应该是 the same year as the year that the novel was published。 太繁琐 也不合用法 这里用that是同位语结构 后面的The Adventures of Huckleberry Finn were published是year的同位语。

miejue

12题 A中or前后要平行 前面是形容词 后面也要用形容词