In this combo photo, the upper part taken by Cai Long and released on Jan. 9, 1981 shows a view of Medog County before its access to any highway in southwest China's Tibet Autonomous Region; the lower part is an aerial photo taken by Sun Fei on Feb. 13, 2021 showing a view of the same county, which has ended its isolation from the outside in 2013 with the opening of a highway. On May 23, 1951, the Agreement of the Central People's Government and the Local Government of Tibet on Measures for the Peaceful Liberation of Tibet (17-Article Agreement) was signed, officially proclaiming the peaceful liberation of Tibet. The year 2021 marks the 70th anniversary of the historic event. (Xinhua)
