The answer is the last sentence
Whites had already began to set up some restrictions on black access to public facilities
Answer: The Huang He River and the Yangtze River.
The Grand Canal is the longest and oldest canal or artificial river in the world. The oldest parts of the canal date back to the 5th century BC, but it was significantly rebuilt between 1271 and 1633. The canal starts at Beijing, passes through Tianjin, Hebei, Shandong, Jiangsu and Zhejiang to the city of Hangzhou. The canal links the Huang He and the Yangtze rivers.