How does the poem Ascending the Mountain express the poet's feelings?

This is a seven-character poem that best represents the desolation and vastness of Du Fu's poems. The first two couplets write about climbing the mountain and seeing the scenery, and the last two couplets express the feelings of climbing the mountain. The scenery is selected by emotion, and the emotion is embedded in the scenery, which fully expresses the poet's complex feelings of wandering for many years, worrying about the country and hurting the time, and being sick and lonely. But the style is magnificent Gao Shuang, generous and vigorous, high-spirited, unique in ancient and modern times.