A yak transports supplies to the advance camp at an altitude of 6,500 meters on Mount Qomolangma, May 20, 2020. (Xinhua/Jigme Dorje)

An ice cave is seen on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma, May 20, 2020. (Xinhua/Jigme Dorje)

Lodro Gyatso, a journalist of the Xinhua News Agency, heads to the advance camp at an altitude of 6,500 meters on Mount Qomolangma, May 20, 2020. (Xinhua/Jigme Dorje)

Photo taken on May 20, 2020 shows ice pinnacles on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma. (Xinhua/Jigme Dorje)

Photo taken on May 20, 2020 shows ice pinnacles on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma. (Xinhua/Jigme Dorje)

Photo taken on May 20, 2020 shows ice pinnacles on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma. (Xinhua/Jigme Dorje)

Photo taken on May 20, 2020 shows ice pinnacles on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma. (Xinhua/Jigme Dorje)

Photo taken on May 20, 2020 shows ice pinnacles on the way to the advance camp at an altitude of 6,500 meters on Mount Qomolangma. (Xinhua/Jigme Dorje)