Question

The boy has to take the pills ______.

1. A.
   every five hours
2. B.
   for five hours
3. C.
   every five-hours
4. D.
   for five-hours

Answer 1

A
服药基础常识，应是每隔几个小时服一次，从句意可知答案应为A选项，意思为每隔5个小时。