What was the purpose of water routes? What are some of the most famous? What advantages did they serve?

the mongolian invasion of china and central asia resulted in a disruption of the silk road as the chinese garrisons lost support from the chinese kingdoms which fell under the mongols. however, as the mongols established a formal dynasty in china, the successors of genghis khan restored the garrisons along the silk road allowing the safe travel caravans again.

russia because it is the biggest state

b is the answer i am assuming

d) true or false question