阅读理解 Hundreds of years ago, life was much harder than it is today. People didn't have modern machines. There was no modern medicine, either. Life today has brought new problems.One of the biggest is pollution  (污染 ) . Water  pollution has made our rivers and lakes dirty. It kills our fish and pollutes our drinking  water.  Noise pollution makes us talk louder and become angry more easily. Air pollution  is the most serious kind of pollution.  It's bad to all living things in the world. Cars,  planes and factories all pollute our air every day. Sometimes the polluted air is so thick that it is like a quilt over a city.  This kind of quilt is called smog (烟雾). Many countries are making rules to fight pollution.  Factories must now clean their water before it is thrown away. They mustn't blow dirty smoke into the air. We need to do many other things. We can put waste things in the dustbin and not  throw it on the ground.  We can go to work by bus or with our friends in the same car.  If  there are fewer people driving, there will be less pollution. (     )1. Hundreds of years ago, life was much harder than it is today because there was much pollution at that time. (     )2. Pollution is one of the biggest problems in today's life. (     )3. Water pollution is the most serious kind of pollution because it's bad to all living things in the world. (     )4. Factories have to clean their water after it is thrown away. (     )5. People can do a Iot of things to fight pollution.