How does the Appalachian Mountains important to the US development

It could attract tourists improving income in the area/country

Explanation:

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.

answer; biological;