To be healthy one must have at least sleep every day.A. eight hoursB. eight hour’sC. eig

问题补充：

To be healthy, one must have at least sleep every day.

A. eight hours

B. eight hour’s

C. eight-hour’s

D. eight hours’

答案：

A. eight hours

B. eight hour’s

C. eight-hour’s

(答案→)D. eight hours’

解析：一般名词所有格 表示人的用’s或’，但是表示时间、金钱和距离的，也可以用表示人的用’s或’，故选D