Demonstrators protest the shooting death of Alton Sterling near the headquarters of the Baton Rouge Police Department in Baton Rouge, Louisiana, U.S. July 9, 2016. (Photo by Jonathan Bachman/Reuters)

Dog Xiaoniu dressed in clothes walks across a street with its owner (not pictured) in Shanghai, December 19, 2014. According to local media, Xiaoniu accompanies its owner to the food market everyday and is able to walk with its hind legs for up to about an hour. (Photo by Reuters/Stringer)

Judy, a black collie whose owner was killed by a train when trying to retrieve her after she slipped her lead. (Photo by Evening Standard/Getty Images). 17th December 1976

The 3D street painting “Crevasse” by artist Edgar Mueller is seen in this undated picture during the “Festival of culture”, 2008 in Dun Laoghaire, Irland. Edgar Mueller put a part of the eastern Pier into the ice age. This project has been supported by the Goethe Institution Germany. (Photo by Edgar Mueller/Getty Images)

Winner of the Sandow bodybuilding competition, Mr. Murray. (Photo by Reinhold Thiele/Thiele/Getty Images). Circa 1905

Two elderly men smoking pipes of opium on a terrace in Korea. (Photo by Bert Hardy/Picture Post/Getty Images). August 1950

A man walks on the Cobb as storm waves break behind on December 13, 2011 in Lyme Regis, England. (Photo by Matt Cardy/Getty Images)

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.