Why are companies and skilled professionals eager to move into urban areas? Good answers can get a bonus 10 points.

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.”

2pi more meters because you find the circumference which is 6pi and 4pi and subtract it and you get 2pi

Can you maybe send me a screen shot of the map? it would really me you. : )