Photo taken on Jan. 27, 2019 shows the "stumbling stones," which are small brass plaques installed on pavements in Germany to commemorate the victims of the Holocaust, in Frankfurt, Germany. In 2005, the UN General Assembly adopted a resolution which designated Jan. 27 as the International Day of Commemoration in Memory of the Victims of the Holocaust, the day when Auschwitz death camp was liberated in 1945. (Xinhua/Lu Yang)