In this paper, the phrase "going back to the Yellow River and crossing the Black Mountain" is similarly expressed in Mulan Poetry. Please tell me the difference between the two contents in expression.

Mulan Poetry tells the story that Mulan disguised herself as a man, joined the army instead of her father, and made meritorious deeds on the battlefield. After returning to Korea, she refused to be an official, but asked to be reunited with her family. This poem enthusiastically praised the strange girl's hard-working and kind quality, her enthusiasm for defending her country, her heroic fighting spirit and her dignified and calm demeanor. It not only reflects the general martial spirit of the nomadic people in the north, but also shows the people in the north's aversion to the long-term separatist war and their desire for a peaceful and stable life. This is eulogizing Mulan, which obviously impacts the prejudice of the patriarchal society. It is a "fantastic poem" (the source of Shen Deqian's ancient poems), full of romance, with a vigorous and simple style, which basically maintains the characteristics of folk songs. Quasi-question and answer is used to describe psychological activities in the poem, which is meticulous and profound; Describe the behavior modality with extravagance and parallelism, with vivid expression; The use of refined spoken language not only expresses a woman's tone, but also enhances the narrative atmosphere and shows the true colors of folk songs. Represents the outstanding achievements of Yuefu folk songs in the Northern Dynasties.