Aerial photo taken on Jan. 4, 2020 shows athletes taking part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province. (Xinhua/Xu Chang)

An athlete takes part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province, Jan. 4, 2020. (Xinhua/Xu Chang)

Vinjar Skogsholm of Norway celebrates after the men's 50km cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province, Jan. 4, 2020. (Xinhua/Luo Yuan)

Athletes take part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province, Jan. 4, 2020. (Xinhua/Xu Chang)

Aerial photo taken on Jan. 4, 2020 shows athletes taking part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province. (Xinhua/Xu Chang)

Athletes take part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province, Jan. 4, 2020. (Xinhua/Luo Yuan)

Aerial photo taken on Jan. 4, 2020 shows athletes taking part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province. (Xinhua/Xu Chang)

Aerial photo taken on Jan. 4, 2020 shows athletes taking part in the cross-country ski competition in Changchun Jingyuetan International Vasaloppet Ski Festival in Changchun, capital of northeast China's Jilin Province. (Xinhua/Xu Chang)