Polish soldiers line up in the cemetery of the victims of the plane crash in Smolensk of Russia at the Powazki Military Cemetery in Warsaw, Poland, on April 10, 2018. Poland marked on Tuesday the eighth anniversary of the plane crash in Smolensk of Russia in which 96 Polish people, including the then-Polish President Lech Kaczynski, were killed. (Xinhua/Jaap Arriens)