Wang Zhihuan's "Liangzhou Ci": "Far above the Yellow River, among the white clouds, there is an isolated city called Wanren Mountain. Why should the Qiang flute blame the willows? The spring breeze does not pass through Yumen Pass." The last two sentences of the poem are literally : The reason why the willows outside Yumen Pass are not green is due to the lack of spring breeze. The spring breeze here refers to the summer monsoon. The monsoon is due to the heat of the sea and land...