J-10 fighter jets attached to an aviation brigade of the air force under the PLA Southern Theater Command taxi in line on the flightline before takeoff during a live-fire training exercise at a military airfield in southwest China on April 12, 2019. The two-day live-fire training covered various air-to-ground attack operations using aircraft guns, rockets and aerial bombs, aiming to hone pilots’ accurate and tactical strike capability. (eng.chinamil.com.cn/Photo by Xie Zhongwu and Zhang Hengping)