The third part of the metrical poem is quite important, and the third part is waist. The waist of the human body was called dragon in ancient times, which is the health preservation of Taoism. Dragon, dragon refers to the waist, in fact, that is to say, the spine, so the third triad of rhyme is equivalent to the human spine. If the third triad is weak, then the whole poem will be invalid.

Rhyme is a popular genre of Chinese poetry in Tang Dynasty, which belongs to a kind of modern poetry, and is named because of its strict metrical requirements. The common types are five laws and seven laws, and there are generally a few words to say.