In Mexico, the population of Mexico City metropolitan area is over 20 million people. The next largest metropolitan area, Guadalajara, has approximately 4.5 million people. This disparity in population sizes makes Mexico City an example of __________.

Primate cities have typically arisen in __________ environments.

A country has a population of twenty million, with a capital city with a population of nine million. That capital city is an example of a __________.

What is a mercantile city?