Let's explain heavenly stems and earthly branches's five elements: A and B are trees, representing C in the east, fire, E in the south, earth, Geng Xu and Jin in the center, Ren in the west, Gui Wei Shui, and earthly branches in the north. It is not so easy to see them, because there are often one, two or at most three heavenly stems in the soil branches. The above words, that is to say, the earthly branches are often composed of several elements. Let's talk about the topic of earthly support, that is, what the earthly support hides and what the five elements hide. Hiding in the Yin: A, C, E, Mao: B, Chen: E, B, Gui: C, G, E, D, I haven't hid in the middle: I, D, B, Shen: G, Ren, E, you: Xin, Xin, Ding Hai. For example, if the strength of Yin is 100, then the strength ratio of A, C and E is about 60:25: 15, and A accounts for a large proportion, so A is called the "vitality" of Yin.