People lay flowers to pay tribute to revolutionary martyrs at the Museum of the War of the Chinese People's Resistance Against Japanese Aggressions in Beijing, capital of China, April 4, 2019, the eve of the Qingming Festival. It is a tradition for the Chinese people to pay respect to ancestors, deceased family members, and national heroes and martyrs at the Qingming Festival, a day for tomb sweeping. (Xinhua/Zhang Chenlin)