What is rhythm? Do you want to use any syllables at the end of each line of this poem?

Parallelism is a set of rules when writing poems in ancient times, just like there are two spaces at the beginning of writing a composition now. These rules seem to have been agreed long ago, and everyone wrote them like this. You can rhyme each sentence or alternate rhymes. For example, the words "golden river in the sea" and "going up a storey still higher" are staggered rhymes, which are catchy to read. Well written, it doesn't matter whether it rhymes or not. For example, only the third scene of "Spring Dawn" does not rhyme, but it is still catchy. Flat tone is a matter of tone. For example, "green" sounds flat with four tones, and "gold" sounds flat with "flat tone".