885 section 20-17

dj830218

LDOCE里给出的twice的用法：

twice as many/much （as sth）

twice the size/number/rate/amount etc

所以twice as fast 应该是not idiomatic

Jessielynn

同样的问题还有OG11-4

A survey by the National Council of Churches showed that in 1986 there were 20,736 female ministers, almost 9 percent of the nation's clergy, twice as much as 1977.

(A) twice as much as 1977                                        
(B) twice as many as 1977                                      
(C) double what it was in 1977                                  
(D) double the figure for 1977 (D)          
(E) a number double that of 1977's

这里的double也是同样的用法