On September 22, 2007, 108 Chinese cities took part in Car-Free Day, a global event held every year, for the first time. China became the world's second-largest auto market and third-largest car-maker in 2006. It has also become the second-largest greenhouse gas producer in the world, and is rapidly catching up with the United States. In this sense, China's participation will greatly promote the Car-Free Day movement. The number of cars on the road is going up rapidly in China. In Beijing, about 1,000 new cars are added to the streets on an average day. Cars certainly offer people plenty of freedom to move around. But in many Chinese cities, appearance of too many cars has turned into a major problem. Getting stuck in traffic jams is an everyday experience for drivers. Even worse is the environmental impact caused by cars. According to a national report, on a "smog day", 79 percent of the air pollution is caused by cars. The growing number of traffic accidents is another problem. Over 100,000 people die from traffic accidents every year in China, which is by far the highest number of road deaths in the world. 108 cities' participation in Car-Free Day shows growing public concern about the traffic and environmental problems caused by cars. On this day, all cars were banned from running in selected areas of the participating cities. People were encouraged to walk, cycle and use public transport. According to experts, the carbon monoxide in the atmosphere produced by cars was reduced by 3,000 tons on Car-Free Day. With cleaner air and smoother traffic flow on the day, more cities will hopefully want to join the event next year. And more people might share the hope that Car-Free Day is not just on September 22, but a possibility 365 days of the year. Car-Free Day in China will   _  .
be held all the year round stop air pollution and traffic jams attract more people to join in reduce the production of cars