Chinese and Japanese choruses jointly sing during a mourning ceremony at the Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders in Nanjing, capital of east China's Jiangsu Province, April 4, 2017. A mourning ceremony was held here by survivors and family members of victims in the Nanjing Massacre during Tomb-Sweeping Day, or Qingming, when Chinese people commemorate their deceased loved ones by visiting tombs. (Xinhua/Sun Can)