They used it for water supply or safe channel developed to pass on water.
Its C Rivers: Nile, Euphrates,Tigris,Indus,Yellow,Yangtze. Hpe it helps! :)
During the period between the Han and Sui Dynasties, in China, is known as the "Period of Disunity." This period is also known as the "Six Dynasties" period. During this period the country was divided into smaller regions. These six regions; Chen, Liang, Southern Qi, Liu Song, Eastern Jin and Wu, were all in conflict with on another. There was not a unified China.
