作者：英吉
Though certain breeds of dog are renowned for their sense of smell, there is often a greater difference in scenting ability between two members of a single breed as there is between members of different breeds.
(A) is often a greater difference in scenting ability between two members of a single breed as there is
(B) is often more difference in scenting ability between two members of a single breed as to find one
(C) is often a greater difference in scenting ability between two members of a single breed than
(D) are often greater differences in scenting ability between two members of a single breed as there are
(E) are often greater differences in scenting ability between two members of a single breed than there is
原文意思：虽然不同的狗嗅觉都很有名，但是在一个breed的member和不同breed的member之间区别还是前者大。
题目分析：有一个比较的并列，由于前面用的greater或more后面用as就不可以了，只有c和e留下来。E后面用there is但是前面用are often greater difference与后面的there is不对应，选C。
