Aerial photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Aerial photo taken on Jan. 12, 2020 shows visitors enjoying the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Aerial photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Aerial photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Aerial photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua

Photo taken on Jan. 12, 2020 shows the winter scenery of the Hukou Waterfall scenic spot. The Hukou waterfall is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Photo:Xinhua