1. From the melody point of view, the main vowel is "An", so this poem is based on An Yun, and the rhyme foot is the rhyme word, that is, "Qian, Xing, Nian and Bian".
2. Poetry rhymes, which makes the work sound harmonious, easy to recite and remember, and has the beauty of rhythm and timbre. In the past, rhyming required the same or the same rhyme part, with some variations. Modern new poetry rhymes without being restricted by ancient rhyming books.