Why do people get headaches in a
crowded, stuffy room? Because they are
breathing bad air. People who breathe bad
air for a long time can get really sick. They
may even get lung cancer and die. People
need fresh air. Fresh air cleans the blood.
For our health's sake, we should all, there-
fore, do our part to fight against air pollution.
空气污染
为什么人们在又挤又闷的房间中会头疼呢?因为他们呼吸着
恶劣的空气。凡是长时间呼吸恶劣空气的人可能会生重病。他们
甚至可能得肺癌死去。人们需要新鲜空气。新鲜空气能净化血
液。为了健康起见，我们每个人都应该尽一己之力为反对空气污
染而努力。