Answer:
a. it gave them access to central Asia
Almost all the rivers of China flow from west to east and flow into the Pacific Ocean. Therefore, already in antiquity, a canal system was built that connected the basins of these rivers. Subsequently, individual sections were merged and completed. That is how the Grand Chinese Channel appeared. It connects Beijing and Hangzhou. Its length is 1774 km, and it is the longest canal in the world. It begins in near Beijing, passes through the cities of Beijing and Tianjin, four provinces - Hebei, Shandong, Jiangsu and Zhejiang, and ends in Hangzhou (Zhejiang Province).