Question

高中英语题Americans eat more than twice as many

Americans eat _________vegetables per person today as they did in 1990
A more than twice B as twice as many
C twice as many as D more than twice as many
应该选D。为什么？ C 哪里不对？

Answer 1

注意下序数词+as+形容词+as是固定用法，表示前者在某一方面是后者的几倍。
故AB形式上都不正确。
这道题是拿美国人现在的蔬菜饮食量和1990年的时候进行对比，注意they did in 1990的前面已经有一个as了，故选项中不能再出现结构中后一个as。所以C是错的，D是对的。