The bicycle is one of the simplest and most useful inventions in the 1 world. What is the most surprising is that it was not invented earlier, although the great inventor Leonardo da Vinci had drawn pictures for bicycles and also for flying machines and some other things. Those things were not produced until long after he died.
A person riding a bicycle uses very little energy to make the bicycle move, and there is no pollution at all when you are riding. In Chengdu, a lot of people rode bicycles to I work twenty years ago. But cars instead of them now. Even so in developed countries, most people do not travel to work by bicycle. It is not because the bicycles 9 are expensive or people feel tired if they ride to work. It is because the number of cars on the roads is becoming larger. It certainly becomes more dangerous to ride a bicycle. As a result, more people put their bicycles away and go to work in their cars. And in this way, the traffic is very crowded when people go to work by car in the morning and go home after work, the situation is becoming worse and worse.
Perhaps the best way to make riding safer and more popular is to create paths only for bicycles, and to make it so difficult and expensive for drivers to take their cars into the city that they will go back to use their bicycles. There has been a special way for bicycles on the road in Chengdu now. I think more and more people will return to ride bicycles to go to work. The air of cities will be much fresher. The sky will be a lot bluer. The people will live much happier lives.
①The bicycles were not produced until long before he died.
②A lot of people in Chengdu rode bicycles to work 20years ago.
③It's not polluted for people to ride bicycles.
④The people in Chengdu can't go to work with a special way by bicycle now.
