What did people mean by slavery being a "necessary evil"

On a map showing the employment density of an urban area that follows the urban realms model, which of following statements best describes what the distribution of jobs might look like? (3 points) jobs closely follow major transit routes. jobs appear to be shifting from the inner to outer core. most jobs are concentrated around the central business district. jobs are distributed roughly in circles. several edge cities contain high numbers of jobs. which of these is not a criticism of the concentric zone model? (3 points) it does not accurately describe cities after the rise of suburban development. it only applies to cities that grew after the development of the automobile. it fails to address the development of cities outside of the united states. it assumes that inner-city areas will always be repurposed instead of abandoned. it places too much importance on the traditional central business district.