Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)

Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)

Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)

Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)

Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)

Aerial photo taken on July 3, 2020 shows a river in the Arxan National Forest Park, north China's Inner Mongolia Autonomous Region. (Xinhua/Liu Lei)