Without air nothing can live.Although we cannot see it,there is air around us.So air is everywhere and it gives life to every living thing.Without it all living things will die.
Bad air makes people ill.We must have fresh air to keep us in good health.In the city,there are a great many people and there are too many cars running on the roads.The gas that the cars give out is full of dirty things.Every day we breathe in the waste gas again and again.This makes us become ill.So people should go outdoors as much as they can.
Besides so many cars,there are many factories,too.From the chimneys of these factories,we can see the smoke is usually black or grey in color.This kind of smoke is dangerous to our health.This is because there are many small harmful things and gas in the smoke.So if we want to keep healthy we must go out to the country to breathe more fresh air.Or we can go up hills to get more fresh air.
没有空气生物都无法生存.虽然我们看不见它,有空气在我们周围.所以空气无处不在,它给生活一切生物.没有水,所有生物都将死亡.
坏的空气使人生病.我们必须有新鲜空气来保持我们身体健康.在这个城市里,有很多人,有太多的汽车在道路上运行.,汽车排出的尾气全是有害的物质.我们每天都不断地呼吸着废气.这使我们生病.所以人们应该尽可能多的去户外走动.
除了这么多汽车,还有很多工厂.从这些工厂的烟囱里,我们可以看到烟通常是黑色或灰色的颜色.这种烟对我们的健康是很危险的.这是因为有许多小的有害物质和气体烟雾.所以,如果我们想要保持健康我们必须去乡下呼吸更多的新鲜空气.或者我们可以去上山来得到更多的新鲜空气.
