OG 11 -85提问

85 Dirt roads may evoke the bucolic simplicity of another century, but financially strained townships point out that dirt roads cost twice as much as
            maintaining paved roads.

B   dirt roads cost twice as much to maintain as paved roads do

C   maintaining dirt roads costs twice as much as paved roads do

D   maintaining dirt roads costs twice as much as it does for paved roads

E   to maintain dirt roads costs twice as much as for paved roads

答案B ,  ETS 解释: 还原这个比较句 dirt roads cost twice as much

to maintain as paved roads  ,但是我总觉得这么还原有问题, 究竟什么东西在比较, dirt roads 和paved roads , 还是cost . 郁闷, 我对这种题目总做不对,有没有什么方法可以告诉我该如何做这种比较的题目比如double , twice 等

多谢指点