Thalia suffers from insomnia. she tries everything, and she finally develops the habit of counting backwards when she wants to sleep but can't. thalia finds that she falls asleep much easier once she starts counting backwards, so she continues to do so. theory suggests that she continues this habit because it results in homeostasis.

The statement above is talking about the Drive Reduction Theory. This theory, proposed by Clark Hull in 1943, talks about a certain drive that develops when a disturbance occurs in an individual's homeostasis or simply put, when someone has physical needs that need to be met. 

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

which of the following is a subsurface event that takes place during the rock cycle?

  cementing  erosion  melting  weathering