The doctor told me to take the medicine.A. every fourth hoursB. each fourth hourC. each fo

问题补充：

The doctor told me to take the medicine.

A. every fourth hours

B. each fourth hour

C. each four hours

D. every four hours

答案：

A. every fourth hours

B. each fourth hour

C. each four hours

(答案→)D. every four hours

解析：

试题分析:考查固定短语。在英语中表达“每．．．”要用every +基数词+复数名词或者every+序数词+单数名词，所以D选项正确．句意：医生告诉我要每四小时服一次药。