Photo taken on Sept 8, 2017 shows the scenery of the Jiudian Gorge in Gannan Tibetan autonomous prefecture, Northwest China's Gansu province.[Photo/Xinhua]

Photo taken on Sept 8, 2017 shows the scenery of the Jiudian Gorge in Gannan Tibetan autonomous prefecture, Northwest China's Gansu province.[Photo/Xinhua]

Photo taken on Sept 8, 2017 shows the scenery of the Jiudian Gorge in Gannan Tibetan autonomous prefecture, Northwest China's Gansu province.[Photo/Xinhua]

Photo taken on Sept 8, 2017 shows the scenery of the Jiudian Gorge in Gannan Tibetan autonomous prefecture, Northwest China's Gansu province.[Photo/Xinhua]

Photo taken on Sept 8, 2017 shows the scenery of the Jiudian Gorge in Gannan Tibetan autonomous prefecture, Northwest China's Gansu province.[Photo/Xinhua]