Which statement is true of diffusion? Diffusion is only important for animal cells. Molecules move from areas of high concentration to areas of low concentration. Only water can diffuse across a cell membrane. Diffusion requires energy input from the cell.

Urban growth invariably feeds increased commercialization and industrialization. it requires continually expanding land areas. when urbanization rates are high, and countries do not have the institutional and managerial capacities or economic wherewithal to manage such rapid growths, they exert intense pressure on the types and nature of the resulting settlements. they contribute to the development of overcrowded slums and shanty towns without adequate essential services and necessary infrastructure.-by asit k. biswas and cecilia tortajada