What images did Du Fu use in the first four sentences of Ascending the Mountain to express his deep sadness about autumn?

Answer: Analysis: The first couplet writes that the autumn wind is urgent, the sky is clear in Wan Li, and there is the sound of apes crying in the distance; The sand beads by the river are lifelike, and birds are hovering in the air. What the poet wrote here is wind, sky, apes, Zhu, sand and birds, which are described by six words: urgency, height, sadness, clearness, whiteness and flying. He painted, colored and listened to the sound from the aspects of hearing, vision and touch, and mobilized various artistic means to paint a magnificent and desolate scene. Turning to the couplet, the poet's vision was broadened, and the atmosphere of mountaineering in late autumn was further written. The leaves are boundless and rustling falls; The river rolled in. The scene was full of sadness, strong and sad, which laid a good foundation for the lyric behind.