A．Sudden population increases in early states.
B．Possible reasons for the formation of early states.
C．Consequences of agricultural land shortages in ancient Egypt.
D．Common political problems of tribes.

A．States often damage the environment of the area they occupy.
B．States engage in trade to obtain necessary goods for their population.
C．States often undergo sudden changes in population.
D．States manage food production for the entire population.

A．To explain why formal legal codes were developed.
B．To explain what caused the destruction of several states.
C．To stress the importance of agricultural workers.
D．To further describe the organization of states.