A survey by the National Council of Churches showed that in 1986 there were 20,736 female minsters, almost 9 percent of the mation'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 E a number double that of 1977's key 请问这里介词for？谢谢 | 
