The beginning of urban studies used a single city to create a concentric zone theory to become a classic model of urban land use. However, this model did not fit wide variety of cities in United States any beyond. What city was the model based upon

The CBD model is based on chicago and does not fit polycentric cities example of stoke on trent.

Explanation:

The CBD model also called as E. burgess model is a model of land use to show the urban social structure.  It was created in 1925, having 5 concentric rings as commuter zone, residential zone, working-class zone, the zone of transition, and factory zone along with the central business district in the center. The model applies to the city of Chicago and is a modified version of the von thunen model of agriculture zones that develops around the city.  The model was criticized for describing the inner city as poor and suburbs as wealthy. It didn't address the urban politics and forces of globalization. It also does not fit the polycentric cities.

This is what i found on google “eightin 1997, the mccaughey septuplets were born in carlisle, iowa. multiple births of as many as eight babies have been born alive, the first set on record to the chukwu family in texas in 1998; one died and seven survived. in 2009, a second set, the suleman octuplets, were born in bellflower, california.” i was surprised about this . i don’t want to have that many babies .