One example of people interacting with their environment is
a.
trade between geographic regions.
b.
clearing away trees to plant crops.
c.
mapping the roads of a region.
d.
reading about regions that have a mild climate.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer

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.