大气层

例句：

1. 1. The Earth's atmosphere is made up of various gases and particles.
   地球的大气层由各种气体和颗粒组成。
2. 2. The weather forecast shows a clear atmospheric layer over the city.
   天气预报显示城市上空有一个清晰的大气层。
3. 3.Air pollution is a major threat to human health and the environment.
   空气污染对人类健康和环境构成了重大威胁。