Researchers are attempting to measure the cognitive abilities of people in late adulthood. They are designing their study to include testing the participants in the morning, when the elderly are typically the most alert, and want to conduct the tests in the homes of the participants. These researchers seem to be considering:

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

What was the length to begin with?