With the _________ (develop) of industry, air pollution is getting more and more serious. In Beijing, many people suffer different kinds of illnesses because_________ air pollution.
Air pollution is caused by the following __________: about half of the problem is caused by vehicles. There are more and more cars, buses on the roads, and they give off __________ (poison) gases.25% of air pollution is caused by factories. Another factor is the smokers. Smoking not only does harm to their health __________ to others. _________ these, about 10% of air pollution is caused by other reasons.
We should take some measures to fight __________ pollution. New fuel can be used to take ___________ place of gas. We can plant more trees. If everybody realizes the__________ (important) of environment and does something to stop pollution, the problem will _______ (solve) .