我国是个多山的国家。地球上的山地面积为陆地面积的六分之一,苏联、美国的山地面积分别为其全国陆地面积的10%和15%左右。我国山区(包括极高山、高山、中山、低山和丘陵),面积为633.7万平方公里,约占全国陆地面积的三分之二,这里有着全国三分之二的县级行政区和三分之一的 My country is a mountainous country. Earth’s mountainous area is one sixth of the land area. The Soviet Union and the United States have mountainous areas of about 10% and 15% of their national land area respectively. China’s mountainous areas (including the extremely high mountains, the mountains, the mountains, the hilly areas and the hills) cover an area of ​​6,337,000 square kilometers, accounting for about two thirds of the land area of ​​the country. There are two-thirds of the county-level administrative regions in the country and one-third One