Answer:
The main contribution was the stock market crash of 1929 that made the United States fall into the Great Depression.
Before developing towns and cities, a society must have agriculture. This feature allows an economic scale to take place and then towns and cities can emerge so that there are different roles for the inhabitants.
Obama was 47 when he got elected.
Explanation:
The strategy of "containment" is best known as a Cold War foreign policy of the United States and its allies to prevent the spread of communism after the end of World War II.
