Rainbow seen at Hukou Waterfall scenic spot in China's Shaanxi
A rainbow is seen at the Hukou Waterfall scenic spot on the Yellow River, which is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces, March 22, 2018. Warmer temperature and melting ice in upper reaches lead to the annual spring flood of the waterfall. (Xinhua/Cao Yang)