请教 96-10-2

2. The world’s deepest cave, Pierre St. Martin in the Pyrenees Mountains, is almost three times as deep _____.

(A) as the Empire State Building is high.

(B) That the Empire State Building is higher.

(C) Is higher than the Empire State Building

(D) And the Empire State Building’s height.

答案：A

但有没人知道~~~Empire State Building is high到底什么结构？

这是倍数表达的其中一种:  倍数+as adj as ...

第一个as是副词: 一样地

第二个as是连词:和.....一样,后边必须加句子.有时谓语可以省略

I am three times as tall as the pig(is).