(210424) -- SANYA, April 24, 2021 (Xinhua) -- Chinese President Xi Jinping, also general secretary of the Communist Party of China Central Committee and chairman of the Central Military Commission, presents People's Liberation Army (PLA) flag and the naming certificate to the captain and political commissar of the Changzheng-18 in Sanya, south China's Hainan Province, April 23, 2021. Xi attended the commissioning ceremony of three naval vessels, the Changzheng-18, the Dalian, and the Hainan, and boarded the vessels after the ceremony. The vessels were delivered to the PLA Navy and placed in active service on Friday at a naval port in Sanya, south China's Hainan Province. (Xinhua/Li Gang)