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).