The synonym for a villa is a manor, a chateau, or a mansion.
According to the doctrine of separation of powers, the U.S. Constitution distributed the power of the federal government among these three branches, and built a system of checks and balances to ensure that no one branch could become too powerful.
He trained rats in the correct route through a maze,then deliberately damaged their brains and observed that this did not inhibit their progress through the maze.
Oligarchy, government by the few, especially despotic power exercised by a small and privileged group for corrupt or selfish purposes. Aristotle used the term oligarchia to designate the rule of the few when it was exercised not by the best but by bad men unjustly.
They both worked as nurses for the Union army.