San Diego (/ˌsæn diˈeɪɡoʊ/ SAN dee-AY-goh, Spanish: [san ˈdjeɣo]; Spanish for 'Saint Didacus') is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States and the seat of San Diego County, the fifth most populous county in the United States, with 3,338,330 estimated residents as of 2019. The city is known for its mild year-round climate, natural deep-water harbor, extensive beaches and parks, long association with the United States Navy, and recent emergence as a healthcare and biotechnology development center. San Diego is the second largest city in the state of California, after Los Angeles.
Qingan County, which belongs to Suihua City, Heilongjiang Province, is located in the intersection of Songnen Plain and Xiaoxinganling in the middle of Heilongjiang Province. It belongs to the middle and upper reaches of Hulan River Basin. It covers an area of 5469 square kilometers and has jurisdiction over 14 townships and 93 villages with a total population of 412000. Hajia Railway, Hay Highway and Jina Highway pass through the border, 170 kilometers away from Harbin. Qingan County belongs to the low mountain and hilly plain area, which belongs to the cold temperate continental monsoon climate, which is suitable for planting rice, corn, soybean and other crops. Qingan is a national green food A-grade rice production base, which enjoys the reputation of "the hometown of green food in China". On January 25, 2019, he was selected as the national "Ping an Agricultural Machinery" demonstration county in 2018. The quality of farmers' cooperatives across the country will be improved and pilot units will be promoted throughout the county.