[求助]大全8

autist

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,

答案是C,我不明白A为什么不对。是因为A选项confusing吗？还是be应该用现在完成时？
（C）

(E) which is believed to be

vagrant

Sammen说的有道理，不过如果直接用 believed to be ，很容易造成修饰对象的混淆，比如邻近的a wingspan of 36 feet

sammen

楼主没有注意到句子的最后有the world has ever seen这是个很明显的完成时态的标志。相类似的还有the world has even been heard.