one person 释义：一个人
谓语动词是应该与one保持一致用单数。例如：
Only one person out of twenty is a farmer. 20个人中只有一个人是农民。
One out of every three persons makes his living from industry. 每3人中就有1人靠工业维生。
①用单数的例句：
One man in five was unemployed. 每五人中有一人失业。
One family in ten owns a dishwasher. 每十个家庭就有一家拥有洗碗机。
②用复数的例句：
Nationwide， one in five adults are illiterate. 就全国范围而言，五个成年人中有一个是文盲。
About one in every 20 people have clinical depression. 大约每20个人中有1个患有临床抑郁症
