The Treaty of Versailles is what officially ended World War I in June 28, 1919. Germany had liability for the damages created, thus, leaving Germany in debt due to their fines. Eventually Germany grew into poverty, people grew desperate, and Hitler stepped up and made huge promises. Hitler decided to disobey the Treaty, and commended a chronological amount of events that led to World War II.
Hoped this helped :)
I'm think its environment, but I don't know for sure :/ sorry
Economy A system of using resources to meet needs
Economics The study of the way that goods, services, and wealth are produced
Government A system of leaders and laws that helps people live safely together
Civics The study of citizenship