When explaining city growth through the multiple nuclei model, geographers acknowledge that modern cities do not always follow strict patterns of growth because of

When explaining the city growth through the multiple nuclei model, geographers acknowledge that modern cities do not follow strict patterns of growth because of : changes to modern trasnportation
Modern transportation will allow the residences from outside the city to came to the big city and back to their home in a small amount of time

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South wales composes a lot of coal in that region.