In december 1968, mao issued a directive on the need to re-educate young people in rural areas in order to re-educate poor middle-land farmers, which led to a large-scale campaign to go up the hill. Between 1955 and the end of the 1970s, nearly 18 million people were decentralized to rural areas. In addition to changing the course of life of a generation of knowledgeable young people, rising up the hills and down the hills has brought about the v

Cardiovascular sci journalsClassification: sci-related knowledge time: attention: (1)What about the cardiovascular sci? The sci periodicals are more academic than academic, have greater influence internationally, and before publishing sci papers, they choose to contribute to the corresponding journal. There are many, but not all, csi periodicals that are suitable for publication, and the grade, division and impact factors of the periodicals are c