2. 1. The Six Dynasties were like a dream, and birds were singing in the air: it means Taicheng, a historic site of the Six Dynasties. It was once the political center of the Jin Dynasty and the place where emperors enjoyed themselves. Now it has faded out of its prosperity and become overgrown with weeds The past vanished like a dream, and only birds sang in the rain. "Empty" is for "dreams". Birds sing and willows grow, and spring rain and grass grow. The prosperity of the Six Dynasties has become a historical passer-by, the dream is gone, and everything is empty. Implies the author's sigh that the Tang Dynasty changed from prosperity to decline. 2, the most ruthless is Taicheng Willow: In the face of the rise and fall of history, willow is still like smoke and fog hanging over the Shili River embankment, as if there is no emotion. Liu Yang's "ruthlessness" reveals people's infinite pain and emotion. The word "still" profoundly reflects the vicissitudes of history. It witnessed the disappearance of a corrupt era in the past, and also predicted the decline of a once "prosperous time". The repetition of history makes the poet's feelings more intense and sincere.