Inclusion relation. Knowledge List and 53 are a publishing house, one of the earliest Quyi series, which contains many books such as 53 and Knowledge List. In addition to the detailed knowledge, there are still some problems, the number is small, but they are almost the same as those in "53". In fact, the knowledge point "53" has been summarized in detail. Fun Art Fairy Beijing Fun Art Fairy Book Planning Co., Ltd. is an educational publishing enterprise specializing in planning and editing educational books. Beijing 53 Gold Book Co., Ltd. is an educational book distribution company specially registered and established by Quyi Line to build a brand and enhance industrial competitiveness. The company is headquartered in Yizhuang Town, Daxing District, Beijing Economic and Technological Development Zone.