Trey's older sister is playing a game with him. she hides the ball they are playing with, and trey quickly loses interest in the game. he makes no attempt to look for the ball and instead picks up another toy that is close by. this suggests that trey has not yet developed:

This suggests that Trey has not yet developed a legitimate understanding of the permanency of tangible objects. This can be evidenced by the fact that Trey lost interest in the ball once it was no longer in his range of sight. He has not yet learned that the object does not just disappear if he is unable to see it.

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