Answer:
The Dust Bowl was the name given to the drought-stricken Southern Plains region of the United States, which suffered severe dust storms during a dry period in the 1930s. As high winds and choking dust swept the region
kublai khan grandson of ghengish khan was first mongol to rule whole china ......he began yuan dynasty in which many reform were made especially in trade and deplomatic relationship and expanded his kingdom
to the south
(3) imperialism
stronger countries felt that they should take over smaller/weaker countries under social darwinism
hope this helps! :-)