People view the displayed Seal of Empress Dowager Cixi at the exhibition titled "Empresses of China's Forbidden City, 1644-1912" during a media preview at the Smithsonian's Arthur M. Sackler Gallery in Washington, D.C., the United States, on March 28, 2019. The exhibition will kick off at the gallery on March 30. (Xinhua/Liu Jie)