Fragrant trees have no flowers, and birds are singing all the way to the spring mountain.
First of all, we should know that this poem was written after the An Shi Rebellion.
The author of the first sentence stood at the head of the city and looked at the scenery, but he saw that a large area of land was barren and overgrown with weeds. It reminds people of Du Fu's "all plants are soldiers" and highlights the scene of our failure.
The third sentence emphasizes the word "nobody", which shows the poet's feelings about the times, and shows that after the Anshi rebellion, no one came here to watch the war and had to let it fall!
The fourth sentence uses the word "empty crow" to write sadness with joy and silence with noise, which fully shows the loneliness and desolation of the mountain road. "Self-falling" and "empty crying" take care of each other, writing the poet's feelings and feelings about the scene before him.