Photo taken on June 19, 2020 shows an unmanned aerial vehicle spraying pesticide above a rice field in Yingkou City, northeast China's Liaoning Province. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

A technician debugs an unmanned aerial vehicle near a rice field in Yingkou City, northeast China's Liaoning Province, June 19, 2020. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

Aerial photo taken on June 19, 2020 shows an unmanned aerial vehicle spraying pesticide above a rice field in Yingkou City, northeast China's Liaoning Province. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

Photo taken on June 19, 2020 shows an unmanned aerial vehicle spraying pesticide above a rice field in Yingkou City, northeast China's Liaoning Province. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

Aerial photo taken on June 19, 2020 shows a technician debugging unmanned aerial vehicles near a rice field in Yingkou City, northeast China's Liaoning Province. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

A technician operates an unmanned aerial vehicle to conduct spraying operation in a rice field in Yingkou City, northeast China's Liaoning Province, June 19, 2020. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)

A technician debugs an unmanned aerial vehicle near a rice field in Yingkou City, northeast China's Liaoning Province, June 19, 2020. Unmanned aerial vehicles were put into use for spraying pesticide in rice field management to enhance the efficiency in Yingkou. (Xinhua/Pan Yulong)