Regards to American and Russian cultures, how is education in the two countries? Why do you think this?

Air pollution: “combustion results in gases such as nitrogen oxides, nitrogen dioxide and particulates. the main causes of air pollution include transport, domestic combustion and industrial processes. pollutants from these sources can cause problems in the immediate vicinity and a distance away.”

This question has already been answered by someone else.here is a link.  hope that it .

I'm pretty sure that the answer is c.