Photo shows a distant view of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, and frozen Rongpu River, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Ziming)

Photo shows a distant view of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)

Photo shows a height monument of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)

Photo shows a distant view of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)

Photo shows a distant view of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Ziming)

Photo shows a distant view of Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Ziming)

Photo shows a distant view of Mount Qomolangma at sunset, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)

Photo shows a distant view of Mount Qomolangma at sunset, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)

Photo shows a monument erected on World Environment Day in 1996, on Mount Qomolangma, the highest peak in the world which stands at an altitude of 8844.43 meters, in southwest China's Tibet Autonomous Region. (Xinhua/Liu Dongjun)