Lunar missions have revealed that the moon has:
a. active volcanoes
b. liquid and solid water
c. extreme temperature variations
d. all of the above

The answer would be C. Extreme temperature variations

Moon's temperature always change from extremely hot to extremely cold following the change in lunar's day/night

In order to survive this extreme temperature, The Astronaut wear a custom made suit that maintain the temperature inside the suit

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.