Performers sing a song during a poetry recitation concert to mark the centenary of the May Fourth Movement in China at Peking University in Beijing, capital of China, May 4, 2019. Saturday marks the centenary of the May Fourth Movement in China. The May Fourth Movement started with mass student protests on May 4, 1919, against the government's weak response to the Treaty of Versailles that imposed unfair treatment on China and undermined the country's sovereignty after World War I. It then triggered a national campaign to overthrow the old society and promote new ideas, including science, democracy and Marxism. (Xinhua/Shen Bohan)