A staff of Chinese drone maker DJI introduces the company's latest crop protection drone, the T20, at a product launch event in Shenzhen, south China's Guangdong Province, Nov. 5, 2019. Besides the new T20 crop protection drone, DJI also introduced an upgraded version of the drone's spray system as well as appertaining service and training plans on Tuesday. (Xinhua/Mao Siqian)