Answer:
Role conflict refers to the psychological effects of being faced with two or more sets of incompatible expectations or demands, while Role overload describes the difficulties of meeting these expectations.
The most likely a better use of David's time in order to prepare for teaching highschool students regarding the American history, is to go to museums alongside studying. Going to museum may be a better way of acquiring historical knowledge that is embedded in the replicas and the remains of ancient objects.
A (make treaties)
D (declare war)
E (establish courts)
A magnifying glass to be able to easily start fires. That would keep you warm, able to cook food, boil water, keep wild animals away from camp, and make you a very valuable teammate.