A visitor turns a knob of a robot model made of scrap fire equipment in Xiamen, East China's Fujian province, on May 11, 2017. The robot model with an infrared sensor system is about 2.7 meters tall, 1.7 meters wide and 500 kg heavy. Firefighters made it in about three months to draw attention to environmental protection by turning trash into treasure. [Photo/VCG]