三一口语七级Pollution

Pollution There are many causes of pollution in our city. 1 Air pollution is a serious problem. Many vehicles and factories cause gas. Smoking is also air pollution and it causes lung cancer 肺癌 Air pollution cause the increase of temperature.：['tempritʃə] How can we prevent air pollution? we can go by bike,subway or walk instead of by car. we can plant more trees and flowers instead of building too many buildings we should let people know the importance of environmental protection by edu