A vehicle-mounted surface-to-air missile system attached to a ground-to-air brigade of the air force under the PLA Central Theater Command launches a ground-to-air missile at mock aerial targets during a live-fire air-defense training exercise in Northwest China’s desert area in mid October, 2019. The brigade takes full advantage of the complex terrain environment and conducts training on such subjects as night maneuver, information networking, operations command, small unit operations and so on. (eng.chinamil.com.cn/Photo by Tan Sicheng)