Which of the following items could serve as a secondary source for a historian studying early chinese history?

a. a bronze plow discovered in the ruins of an ancient chinese city
b. a chart created in ancient china to track a city's growing population
c. an essay about china's first emperor written by a university professor
d. an announcement written for an early chinese emperor to deliver to his subjects

C. An essay about China's first emperor written by a university professor

Explanation:

A university professor's research and analysis is more credible than;  

A bronze plow discovered in the ruins of an ancient Chinese city

A chart created in ancient China to track a city's growing population

An announcement written for an early Chinese emperor to deliver to his subjects

why do you think kush in nubia is not as well-known as egypt?

answer: (fluidity)is the correct answer.

explanation: because of this characteristic, success on the battlefield depends in large part on the ability to adapt to proactively change events to our advantage as well as to react quickly to constantly changing conditions