Nowadays more and more families own private cars. Private cars, as the product of modem civilization, have been playing a vital role in people's daily activities. First, private cars are a convenient means of transportation. You can go wherever you like. Secondly, there is no doubt that private cars will have a great impact on the economic growth. The rapid car industry growth will contribute much to keeping the country's economy growing at a higher rate in the near futrue.
　　But every coin has two sides. The development of the private cars will bring about a series of problems. For example, the polluted air given off by cars will do great harm to our health, too many private cars will lead to traffic jams and a great deal of energy will be wasted and so on.
　　So I think we should take advantages of private cars and make them serve us better. Meantime we hope that satisfactory solutions to these negative problems will be found soon.