Aerial photo taken on April 23, 2020 shows a rainbow over the Hukou Waterfall scenic spot on the border area between north China's Shanxi and northwest China's Shaanxi provinces. (Photos: Xinhua/Tao Ming)

Aerial photo taken on April 23, 2020 shows rainbows over the Hukou Waterfall scenic spot on the border area between north China's Shanxi and northwest China's Shaanxi provinces.

Aerial photo taken on April 23, 2020 shows a rainbow over the Hukou Waterfall scenic spot on the border area between north China's Shanxi and northwest China's Shaanxi provinces.

Aerial photo taken on April 23, 2020 shows rainbows over the Hukou Waterfall scenic spot on the border area between north China's Shanxi and northwest China's Shaanxi provinces.