College volunteers join in a desert control activity in Xilingol, North China’s Inner Mongolia autonomous region, July 19, 2018. [Photo/Xinhua]

Photo taken on July 19, 2018 shows sand barriers at a desert control area in Xilingol, North China’s Inner Mongolia autonomous region. [Photo/Xinhua]

College volunteers join in a desert control activity in Xilingol, North China’s Inner Mongolia autonomous region, July 19, 2018. [Photo/Xinhua]

College volunteers join in a desert control activity in Xilingol, North China’s Inner Mongolia autonomous region, July 19, 2018. [Photo/Xinhua]