We spend an extraordinary amount of time in buildings that are extremely controlled environments, like this building here -- environments that have mechanical ventilation systems that include filtering, heating and air conditioning.
我们花费大量时间 在建筑上 来严格控制环境 就像我们现在所在的这栋建筑-- 有机械通风系统控制环境 系统包括了过滤 暖气装置以及空气调节装置