[讨论] 补充题 128

128. During the Renaissance, scholars were uncertain as to the location of Troy, and by the eighteenth century many historians doubted that Troy had ever existed.

(A) doubted that Troy had ever existed

(B) doubt that Troy has ever existed

(C) were in doubt as to the existence of Troy

(D) were doubtful concerning Troy’s existence（A）

(E) had doubts about Troy’s ever existing

最开始简单的选A， 但是第2遍做大全开始推敲，感觉选项C的对应更好。

scholars were uncertain as to the location of Troy

many historians were in doubt as to the existence of Troy

请讨论～

as to 就表达了　about 的含义，

doubt, existance 都有相应的动词形式，为什么要用抽象名词形式呢？