The end of the sentence rhymes. The Modern Chinese Dictionary explains this. There are many details about rhyme in Rhyme. I remember when I was a beginner in writing metrical poems, a friend said: the rhyme of metrical poems must be flat and even. At that time, while I was surprised, I seemed to think that what he said was somewhat absolute and far-fetched. Later, it was found that the rhymes in metrical poems were generally flat and even. In ancient times, rhyming was also useful, but this usage was rare and gradually shelved by people. Therefore, when ordinary people write metrical poems later, if they use rhyming feet, they will be considered to be out of rhythm.
Rhyme is also called vowel. Vowels are divided into three parts: the beginning, the belly and the end. Generally speaking, as long as the rhyme ending is the same and the rhyme belly is the same or similar, the rhyme head is not considered. The rhyme in metrical poems is different from that in modern Mandarin and Xinhua Dictionary. Some words have the same pronunciation and vowels, but they don't belong to the same rhyme. And some words look different in pronunciation, but you look them up in Phonology and Rhyme, but they belong to the same rhyme department. Therefore, to write metrical poems, we must first master some simple phonological knowledge. It may be easier for southerners to learn to write metrical poems than northerners, because there are still some ancient sounds in some dialects in Wu, Fujian and Guangdong today, and many of these ancient sounds belong to the same rhyme department in The Compendium of Rhyme.