People take care of tree saplings in the field restored from a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

People work at a restoration site of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

A man works in a field for sowing after restoration of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

People sow grass seeds in the field restored from a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

People sow grass seeds in the field restored from a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

Aerial photo shows a field for sowing after restoration of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

Aerial photo shows people working in a field for sowing after restoration of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

People work at a restoration site of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)

Photo shows a field for sowing after restoration of a disused mine in Maquanzi Town of Qinglong Manchu Autonomous County, north China's Hebei Province, Sept. 5, 2020. In recent years, Qinglong Manchu Autonomous County has focused on restoring open pits and reclaimed 8,762 mu (about 584 hectares) of land. (Xinhua/Yang Shiyao)