What geographic feature protected Rome from an invasion from the north?
the
tiber River
the Italian Alps
the hills of Rome
the Tyrrhenian Sea

Which of these is not a criticism of the concentric zone model? 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 assumes that inner-city areas will always be repurposed instead of abandoned. it places too much importance on the traditional central business district.