我国陆地边境线东起辽宁省丹东市的鸭绿江口 ,西迤广西壮族自治区防城港市的北部湾畔 ,总长度约２ ２万公里。其间或纵横、或穿越着长白山、大兴安岭、蒙古高原、阿尔泰山、天山、帕米尔高原、喀喇昆仑山、喜玛拉雅山、横断山和云贵高原等十几座高大山脉和高原。在这些山脉和高 The land borderline of China starts from the Yalu River estuary in the east of Dandong City, Liaoning Province, and the bank of the Beibu Gulf in the west of Fangchenggang City, Guangxi Zhuang Autonomous Region, with a total length of 22,000 kilometers. In the meantime or vertically and horizontally, or through the Changbai Mountain, Daxinganling, the Mongolian Plateau, Altai, Tianshan, Pamirs, Karakorum, Himalayas, Hengduan Mountains and the Yunnan-Guizhou Plateau and a dozen high mountains and plateaus. In these mountains and high