What helped the Khans maintain communication over long distances during the height of the Mongol Empire? A.
The Khans built an extensive network of roads throughout the territories that they conquered.

B.
The Khans required their subjects to learn to read and write so they could understand the empire's laws.

C.
The Khans developed a postal system that allowed them to efficiently send messages throughout the empire.

D.
The Khans forced people to learn Mongolian so that they could speak to people from other regions.

C.  The Khans developed a postal system that allowed them to efficiently send messages throughout the empire.

Explanation:

Communication over long distances during the height of the Mongol Empire was done through postal-relay horse stations called Örtöö. These postal relay horse station spreads throughout the empire which is the main source of communication between khans and their generals and army officers. This source of communication is the best at that time which is considered as the fastest mean of communication.

native american contribution: the patriots from britain learn how to hunt, fish, and introduce diversity within cultures.

african americans: indirectly introduced the idea of diversity to americans. africans coming to america because of slavery taught white americans that people come from different backgrounds and colors. it also built america's economic stability for a great period of time. 

women: make america what it is today. there are some societies that are in the world currently that do not give women the same right we give women here in the united states. because women have rights here in the united states, other countries' citizens strive to come to america, especially women, since they have equal rights in the united states. this is important because america is seen and desired by many in the world. 

children: children are our future. we learn from our elders and carry out things the same or differently learning from america's history. we continue tradition and change tradition if it is needed.