Raising a flag over the Reichstag is a historic World War II photograph taken during the Battle of Berlin on 2 May 1945, by Yevgeny Khaldei.

An Islamic religious leader and rebel supporter (R) chant to rally rebel fighters awaiting a rumored Libyan Army advance April 11, 2011 between the crucial towns of Ajdabiyah and Brega, Libya. Rebels continued to hold the strategic town of Ajdabiyah a day after NATO air power struck army troops loyal to Libyan ruler Moammar Gaddafi nearby, helping the rebels secure the city. (Photo by Chris Hondros/Getty Images)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Russian-born artist Vlad Korneev poses for a picture in his museum called “Designpanoptikum, Museum For Extraordinary Objects” on November 4, 2010 in Berlin, Germany. The museum displays objects whose outward appearance was determined by function rather than form, he says, and are the result of a collection he started while accumulating props for his photographic works. (Photo by Sean Gallup/Getty Images)

Impala pictured in the Kruger National Park on December 7, 2007 in Mpumalanga, South Africa. (Photo by Warren Little/Getty Images)

White lioness Azira lies in the cage with her three white cubs, on February 4, 2014. Zoo owner Andrzej Pabich says white lions often have defects that prevent giving birth, or the mother rejects her cubs, but Azira has been patiently feeding and caring for her little ones. (Photo by Czarek Sokolowski/Associated Press)

A woman carries a water pump to work on February 11, 2017 in Almolonga, Guatemala. The Mayan town in the western highlands district of Quetzaltenango has surged in prosperity in recent years with high-productivity vegetable farming, exporting much of its excess crops to neighborning El Salvador. (Photo by John Moore/Getty Images)

Artists perform during the Closing Ceremony of the Rio 2016 Olympic Games at the Maracana Stadium in Rio de Janeiro, Brazil, 21 August 2016. (Photo by Sergei Ilnitsky/EPA)