A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

Britain's Queen Elizabeth boards a train at Kings Cross station in London, in this December 17, 2009 file photo. Queen Elizabeth celebrates her 90th birthday on April 21, 2016. (Photo by Stefan Rousseau/Reuters)

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Kenya, Saturday, April 30, 2016. A six-story residential building in a low income area of the Kenyan capital collapsed Friday night under heavy rain and flooding, killing at least seven people and injuring over 100 others, Kenyan officials said. (Photo by Sayyid Abdul Azim/AP Photo)

A woman shoots her rifle at a forest shooting range near the village of Visnova, Czech Republic, June 9, 2016. (Photo by David W. Cerny/Reuters)

Rita Ora attends the World Premiere of JEREMY SCOTT: THE PEOPLE'S DESIGNER, presented by The Vladar Company and Quintessentially at the TCL Chinese Theatre on Tuesday, September 8, 2015, in Hollywood, Calif. (Photo by Matt Sayles/Invision for The Vladar Company/AP Images)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

A boy covers his head with fallen leaves as he enjoys a stroll with his family in a park in downtown Frankfurt, Germany, November 6, 2016. (Photo by Kai Pfaffenbach/Reuters)