Los Angeles (US: /lɔːs ˈændʒələs/ (listen) lawss AN-jəl-əs;[a] Spanish: Los Ángeles [los ˈaŋxeles], lit. 'The Angels'), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world's most populous megacities. Los Angeles is the commercial, financial, and cultural center of Southern California. With a population of roughly 3.9 million residents within the city limits as of 2020, Los Angeles is known for its Mediterranean climate, ethnic and cultural diversity, being the home of the Hollywood film industry, and its sprawling metropolitan area. The city of Los Angeles lies in a basin in Southern California adjacent to the Pacific Ocean in the west and extending through the Santa Monica Mountains and north into the San Fernando Valley, with the city bordering the San Gabriel Valley to its east. It covers about 469 square miles (1,210 km2), and is the county seat of Los Angeles County, which is the most populous county in the United States with an estimated 9.86 million residents as of 2022.
Qilian County, which belongs to Haibei Tibetan Autonomous Prefecture of Qinghai Province, gets its name because it is located in the hinterland of the middle part of Qilian Mountains. It is adjacent to the Gansu Hexi Corridor, the primary passage of the ancient Silk Road, to the north, so it is known as the "north gate" of Qinghai. Qilian County covers an area of 14000 square kilometers, accounting for 41% of the total land area of the whole state. It has jurisdiction over 45 administrative villages in 4 townships and 3 towns, with a total population of 50,000 as of 2013, with 15 ethnic groups, including Han, Tibetan, Mongolian and Hui, with ethnic minorities accounting for 79.2% of the population. The average elevation in the territory is 3169 meters, the county seat is 2787 meters above sea level, the annual average temperature is 1 ℃, and the annual precipitation is about 420mm, which is a typical plateau continental climate. Qilian is an important resource-rich area in Qinghai Province. A variety of mineral resources, known as "China's Ural", is a key county in the development of resources in the province. "Qilian" system