问题补充：
He attends the evening class , that is, Monday, Wednesday and Friday.
A. every three days
B. every the second day
C. every two day
D. every other day
答案：
A. every three days
B. every the second day
C. every two day
(答案→)D. every other day
解析：考查词组：每隔几天是every+序数词+单数名词，every+基数词+复数名词，BC都不对，A是每隔三天，D是每隔一天，结合句意：他星期一，三，五上夜校，就是每隔一天。选D。
