Aircrafts carrying soldiers of the Chinese People's Liberation Army (PLA) for a routine troop rotation land in south China's Hong Kong, Aug. 29, 2019. The Hong Kong Garrison of the Chinese People's Liberation Army on Thursday morning completed the 22nd rotation since it began garrisoning Hong Kong in 1997. (Photo by Cui Jian/Xinhua)

Chinese People's Liberation Army (PLA) conducts a routine troop rotation in south China's Hong Kong, early Aug. 29, 2019. The Hong Kong Garrison of the Chinese People's Liberation Army on Thursday morning completed the 22nd rotation since it began garrisoning Hong Kong in 1997. (Xinhua)