Many years ago, people lived a hard life. They couldn't use modern machines, because there was 1one at that time. Today people have a better life but there are new problems. One of biggest problems is it has 2our rivers and lakes dirty. It kills our fish and affects our 3water. We call it water pollution. Noise pollution makes us talk more 4and become angry 5. Air pollution is the most serious kind of pollution. It affects all living things in the world. Machines and factories 6our air every day. Sometimes the pollution is so 7that it is like a blanket (毯子)covering a city. Many countries are making new laws to reduce pollution. We must clean 8water before we 9them into some place. We need to do many other things to protect our environment. We must put rubbish into dustbins 10throwing them about. We can go to work by bus, on foot, or with friends in a car. If we do like that every day, our environment will be better.