In this combo photo, the upper part taken by Wang Chunde in 1959 and the lower part taken by Purbu Zhaxi on Aug. 13, 2021 shows a view of Barkhor Street in Lhasa, southwest China's Tibet Autonomous Region. 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)