air handling conditioning of air

例句：

1. 1. The air is getting colder and the sky is turning darker.
   空气越来越冷，天空变得越来越暗。
2. 2. The scientist conducted an experiment to study the effects of air pollution on human health.
   科学家进行了一项实验，研究空气污染对人类健康的影响。
3. 3. Air travel is becoming more popular as people seek to save time and money.
   随着人们寻求节省时间和金钱，航空旅行正变得越来越受欢迎。