Answer:
A. We constructing the great wall in constructing large ships for exploration
Explanation:
1 Majority of the existing Great Wall of China was built in the Ming era.
#2 Seven epic voyages were led by the great Chinese admiral Zheng He.
#3 Ming period saw great development in printing.
#4 The most comprehensive book on traditional Chinese medicine was written.
The Ming Dynasty ruled China from 1368 to 1644 A.D., during which China's population would double. Known for its trade expansion to the outside world that established cultural ties with the West, the Ming Dynasty is also remembered for its drama, literature and world-renowned porcelain.
A secondary source could be someone that maybe discovered the body or is doing evaluations to see why or how he died, like a doctor for instance it would be a secondary source because............the doctor was not there and he did not watch so....and if he wrote about it then that would be a secondary source! :) <3 hope this helps!
Jazz was criticized in the 1920's for promoting promiscuity and alcohol use.
hope this helps.