碧空万里

Explanation: Miles: refers to the area, long distance. Describe the weather was fine. 　　Source: Quanyan Chi "walked down the altar of Zhou Enlai rest and recreation": "Bingfeng buildings, clouds roam the meantime; azure skies, and snow reflect up and down, turned into circulation with colorful light." 　　Examples: Two million years ago, the day ~ no clouds, the sun parched the earth. ★ "Yellow River Elephant"