What was Thomas Edison's economic effect ( one paragraph long )

William poole believes economics should be taught in schools because students will learn

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.

Which presentation option is also known as a screen of a presentation?