Turtle book
Remarks: Kun Gan: The Book of Rites Li Yun quoted a passage from Confucius: "It is a song of the past, but not enough to view Yin Dao." I have kungan. The meaning of kungan ... I think so, too. "The word' kungan' in the sentence is by no means an inverted sentence of the word' gankun', nor can it be equated with' yin and yang', but refers to the hexagrams represented by Kungua and Gangua.
╮ (╯ _ ╰) ╭ If you are writing a novel or something, you will feel great if you use the names of mountains and rivers, the sun and moon of Gankun, the dragon sequence diagram and the sun and moon swallowing diagram, although I made up these names.