The World Health Organization keeps track of what countries have cases of polio and when they occur, and what the frequency of--So, this is a map from a few years ago and there are efforts that occur occasionally.

世界卫生组织一直跟踪记录,发生小儿麻痹症的国家及发病时间,以及发生的频率,那么,这是从几年前开始统计的,一个地图,这里是一些偶然产生的成就

耶鲁公开课 - 生物医学工程探索课程节选

It was the World Health Organization, or WHO, which led this effort.

世界卫生组织,或者叫WHO,正在努力完成这项工作

耶鲁公开课 - 生物医学工程探索课程节选