According to analysts, an alliance between three major personal computer companies and most of the nation’s largest local telephone companies would enable customers to receive Internet data over regular telephone lines with speeds much higher than is currently possible.

A. with speeds much higher than is

B. with speeds that are much higher than are

C. at much higher speeds as are

D. at much higher speeds than that (E)

E. at speeds much higher than are

answer：E

我不明白为什么than后面要补出are呢？much前面的是名词speeds那than后面补也应该是个名词吗？

than后面补出are可以理解，不过还是不明白为什么名词和句子进行比较也可以?

就是呀，我也不明白。

首先，意见统一的是at a speed of 只能这么用。

再者，不是名词和句子进行比较， 而是名词跟名词比，由于名词一样，后面一个可省略，不会造成歧义。