1. why might scientists repeat a
study under slightly different
circumstances than the
original?
a. to form a research question
b. to study changes over time
c. to confirm the hypothesis
d. to create the right conditions

It’s because it’s was very fun

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.