Students practice operating a drone at Kaiping Primary School in the Kaiping District of Tangshan, north China's Hebei Province, March 15, 2018. The Education Department of Kaiping has purchased more than 100 drones, which are used to hold extracurricular activities at schools in the district (Photo: Xinhua)

A teacher introduces the techniques of drone operating at Kaiping Primary School in the Kaiping District of Tangshan, north China's Hebei Province, March 15, 2018. The Education Department of Kaiping has purchased more than 100 drones, which are used to hold extracurricular activities at schools in the district (Photo: Xinhua)

A teacher introduces knowledge about drone at Kaiping Primary School in the Kaiping District of Tangshan, north China's Hebei Province, March 15, 2018. The Education Department of Kaiping has purchased more than 100 drones, which are used to hold extracurricular activities at schools in the district (Photo: Xinhua)