17.   In the 1980’s the rate of increase of the minority population of the United States as nearly twice as fast as the 1970’s.

(A) twice as fast as

(B) twice as fast as it was in

(C) twice what it was in

(D) two times faster than that of（C）

(E) two times greater than

这道题为什么 b 不对啊？总觉得B 越读越像答案？？？求教！！！！！！！！

The rate is fast错。fast修饰RATE不好,只能用high,great等等形容词修饰number,

rate, size, volume等数词。

what的用法: 代替了the rate that

选C