A fighter jet attached to an aviation brigade of the air force under the PLA Eastern Theater Command soars into the sky during a round-the-clock flight training exercise on September 17, 2020. Airmen with the aviation brigade fully studied the changes in weather, bird activity, equipment performance and other aspects brought about by seasonal changes, so as to practice the basic skills of aerial combat to the best. (eng.chinamil.com.cn/Photo by Fu Gan)