People visit Tianchi Lake on Changbai Mountain in Northeast China's Jilin Province, June 14, 2019. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)

Photo taken on June 14, 2019 shows Tianchi Lake on Changbai Mountain shrouded in fog in Northeast China's Jilin Province. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)

People visit Tianchi Lake on Changbai Mountain in Northeast China's Jilin Province, June 13, 2019. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)

A tourist poses for photos at Tianchi Lake on Changbai Mountain in Northeast China's Jilin Province, June 14, 2019. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)

Photo taken on June 6, 2019 shows the frozen Tianchi Lake on Changbai Mountain in Northeast China's Jilin Province. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)

Photo taken on June 14, 2019 shows Tianchi Lake on Changbai Mountain in Northeast China's Jilin Province. With the temperature rising, Changbai Mountain Nature Reserve enters its tourism season. Many tourists from home and abroad come to enjoy its magnificent scenery and the view of Tianchi Lake. (Photo: Xinhua)