Final answer:
The role and significance of cities have changed over time due to economic forces and specific industries. Primate cities exist as expressions of national sentiment and heritage, but not all capital cities are primate cities.
Step-by-step explanation:
The question is about the changing role and significance of cities over time. In the past, cities were primarily focused on providing for the material well-being of their citizens, but today, their function has become secondary. Cities now primarily grow and develop due to economic forces, and their importance is measured by factors like population size and economic activity. For example, the growth and development of cities were historically influenced by specific industries or trade situations. Cities like Pittsburgh, Chicago, and Detroit were defined by their core industries, such as steel, meat packing, and automobile manufacturing. These cities faced common challenges associated with rapid expansion, including housing, transportation, and class inequalities. Additionally, the concept of a primate city, which is more than twice as large as any other city in a country, can also be considered. However, it's important to note that not all capital cities are primate cities. The primate city represents a national feeling and heritage.