【题目】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
在线课程【答案】D
【解析】
试题分析：句意：美国人现在每天吃的蔬菜是1990年的两倍。倍数表达方式：倍数+as…as…，第一个as后加形容词或副词，第二个as后加比较对象，故选D.