Group 1 - The geographical features along the 30°N latitude in China create a unique environment that supports dense population and early agricultural civilization [1][2] - The Qinghai-Tibet Plateau, known as the "Roof of the World," plays a crucial role in enhancing monsoon rains, contributing to the fertile conditions along the 30°N line [1] - The Wushan Mountain Range serves as a boundary between different topographical levels and significantly influences local climate, hydrology, and ecosystems [1][2] Group 2 - The Yangtze River, flowing east of the Wushan Mountains, has deposited sediments that formed the expansive Yangtze River middle and lower plains, making it one of the most economically vibrant and culturally rich areas in China [2] - The mountains in this region are ancient, shaping world-renowned natural and cultural landscapes, and embodying the harmony between humanity and nature [2] - The mountains along the 30°N latitude are not only geographical features but also represent the spiritual backbone of the Chinese people, symbolizing resilience and cultural heritage [3]