11-verba-怪点

75. In a recent poll，86 percent of the public favored a Clean Air Act as strong or—stronger than the present act.

(A)  a Clean Air Act as strong or stronger than

(B)  a Clean Air Act that is stronger, or at least so strong as，

(C)  at least as strong a Clean Air Act as is

(D)  a Clean Air Act as strong or stronger than is

(E)  a Clean Air Act at least as strong as

Ans: E

我想请问
            为什么选项E中
            的第二的as后面不用加is