Answer:
Chang'an to Duhuang
Explanation:
The city of Marakanda to Antioch are linked through the Silk Road which is known for its prevalent silk trade. The Silk Road is a trade route in the Asian-Pacific region which connects the East to the West.
The cities through which an individual can travel to get to Marakanda and Antioch are Chang'an to Duhuang
This is an example of a closed system
I thought you were asking what comes after 23 );
Profound social economic changes occurred