Photo taken on April 7, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Photo taken on April 7, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Photo taken on April 7, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Photo taken on April 7, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Photo taken on April 7, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County, northwest China's Gansu Province. (Xinhua/Fan Peishen)