Answer:
Mansa Musa developed cities like Timbuktu and Gao into important cultural centers. He also brought architects from the Middle East and across Africa to design new buildings for his cities. Mansa Musa turned the kingdom of Mali into a sophisticated center of learning in the Islamic world.
I'm no expert on this, but I would say conquoring other lands and kingdoms. Going into battles and winning. Taking over cities, and stealing their items. They were very powerful back then, and demanded respect.
~Silver
World War I took the United States out of a recession into a 44-month economic boom. 30 Before the war, America had been a debtor nation. After the war, it became a lender, especially to Latin America. U.S. exports to Europe increased as those countries geared up for war.
-google
The option that does not explain why a large part of the Great Plains became known as the "Dust Bowl" would be that "<span>The soil of the Great Plains was too rocky to support farming," since the soil was (usually) relatively fertile. </span>
