Most energy used in the U. S. is produced from coal. There are 315,000,000 people in the U. S. It is estimated that one person is responsible for using 2000 lbs of coal per year. For every 100 lbs of coal burned, 2.5 lbs of sulfur go into the atmosphere. How much sulfur is put into the air by coal burning each year for all the people in the U. S.?

A. describe the model of urban structure most often observed in mega-cities in developing countries. explain how this model differs from common urban structures in north america. b. describe at least two factors leading to the growth of mega-cities in developing or least-developed countries. c. identify and explain two factors that led to the formation of squatter settlements in mega-cities in developing countries.