Chief Executive of the Macao Special Administrative Region (SAR) Chui Sai On (3rd R, front), Deputy Head of the Liaison Office of the Central People's Government in the Macao SAR Yao Jian (3rd L, front) and Shen Beili (2nd R, front), commissioner of the Ministry of Foreign Affairs in the Macao SAR, attend a flag-raising ceremony to celebrate the 19th anniversary of Macao's return to the motherland in Macao, south China, Dec. 20, 2018. (Xinhua/Cheong Kam Ka)