Villagers are much healthier than people who live in towns．One reason for this is country air is fresher than the air in smoky 1 ．The villagers breathe fresh clean air all day in the fields, but the air the townsmen 2 is always full of smoke and dust．
We cannot live without air．If we are stopped from breathing 3 for five minutes, we will die．Bad air means bad health and certain kinds of 4 , which may kill us in the end, 5 they may not kill us at once．
We all 6 what unpleasant feelings we get if we stay a long time in a closed, crowded room．After a time, we begin to feel very 7 ．and can hardly keep our eyes open．The longer we stay, the worse we feel．How nice it is when we get 8 into the fresh air outside!
We must keep our windows open, so that the 9 in our house is always fresh, and we should breathe as much as we can in the open air．For people who breathe 10 air for a long time often get very ill and die of lung diseases．
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