From the picture above, we can see that people are coughing in the polluted air. With air pollution worsening than before, pm 2.5 has become a usual word for us. Needless to say, people do not like this word, as the content the word represents does great harm to people’s health.
　　As the polluted air does affect our health, we should take some measures to make the air cleaner. On the one hand, we should take mass transit instead of driving a car. According to a recent study, vehicle exhaust is a main source of air pollution, so if vehicle exhaust reduces, the air will become cleaner. On the other, more trees should be planted to absorb the tiny dust in the air, which surely will make the air cleaner.
　　Protection of the environment needs constant efforts by every people on the planet. Only in this way can we have cleaner air and more livable environment.