一道JJ题，这类题一直不会！！！

xixi86813

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.     at speeds much higher than are

选E

关于正确答案结构，
            at speeds much higher than are currently possible, than后面跟着 are +形容词，这样的组合是怎么一回事？than跟着的内容我老是很迷惑，谁能帮我讲解一下！！！小女子不胜感激！！！

hanheli

than后面省略了speeds that。