For example, the book of songs "Xiaoya Cai Wei"
The main place to emphasize the relationship between levels is in metrical poems, such as the five elements, seven laws, five elements and seven laws, such as Du Fu's Ascending the Mountain (apes whimper in the wide sky and the birds return on the white sand in clear lake). The endless trees are rustling leaves, and the Yangtze River is rolling unpredictably. Li in the sad autumn scenery, a wanderer all the year round, lives alone on the high platform in today's illness. After all the hardships and hatred, the white hair is full, and the wine glasses are damaged. )