Question: How long is the river that flows into the extensional sedimentary basin located in the northern part of the South China Sea?
Sentence (from "Pearl River (China)"): Measured from the farthest reaches of the Xi River, the Pearl River system is China's third-longest river, 2400 km , after the Yangtze River and the Yellow River, and second largest by volume, after the Yangtze.
Relevant evidence: Yes