1.  Riding won't produce harmful gas and is friendly to environment\

2.  The gas is produced every time you use energy, so for our normal people, we don't have the ability to call up the whole world, but we can start to save energy from ourselves.

3.  The heavy traffic produces much noxious gas such as nitrogen and carbon dioxide.

4.  First and foremost, most private cars produce harmful gases, posing threat to our environment.

5.  Many cars produce harmful gases from the engine.

6.  We burn them to produce energy while producing a gas which can pollute the air such as carbon monoxide.

7.  In addition large amount of cars produce much waste gas so that the quality of air has become worse and worse .

8.  While more and more greenhouse gases are produced, a series of pollution problems happen to us such as drinking water shortages, glaciers melting faster, the area of continent decreasing.

9.  Buses, cars are producing waste gas without stop.

10.  The green car will produce less waste gas and then finally be totally clean, which can be an effective method to solve the pollution problem.