Picking chrysanthemums under the eastern fence, you can leisurely see Nanshan Mountain. The poem that embodies space in Guofeng and Xiaoya is "picking chrysanthemums under the east fence and leisurely seeing the Nanshan Mountain." Verses are the sentences that make up poems. Poems usually follow the format of poetry and limit the number of words in each sentence. The earliest poems in China have a rhymed verse structure with strict metrical requirements. For example, the poems in the pre-Qin period generally have four words per sentence, which are found in the "Book of Songs". Later it developed into five-character or seven-character rhymed poetry, which is found in Tang poetry.