Why did merchant classes begin to rise during the Ming?

Explanation:

In 1352, Zhu joined one of the many insurgent forces that had risen in rebellion against the Mongol-led Yuan dynasty. ... The last Yuan emperor fled north into Mongolia and Zhu declared the founding of the Ming dynasty after razing the Yuan palaces in Dadu (present-day Beijing) to the ground.

although world war i began in 1914, the united states did not join the war until 1917. the additional firepower, resources, and soldiers of the u.s. to tip the balance of the war in favor of the allies. remaining neutral. when war broke out in 1914, the united states had a policy of neutrality.