It is said in ancient times that the Yellow River carp will turn into a dragon when it jumps over the Longmen. Yaya Shi Yu: "As the saying goes, a fish jumps over the Longmen, and after crossing the Longmen, it is a dragon. Only carp is possible." Li Yuan's Creeping Fan in the Qing Dynasty: "Carp ... every year, Ji Man climbs the Longmen upstream in the yellow, and the skyfire burns its tail from behind, then it turns into a dragon." Later, I used "carp yue longmen" as a metaphor for promotion, promotion and other things. Later, the metaphor went upstream; Make progress.