A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

The Last Bell (we mean the bell that informs the pupils about the beginning or the ending of the lessons) is the traditional feast of the Russian pupils who leave the school. The Last School Bell feast occurs in the end of May, when the school year has already finished, but the final examinations have not begun yet. Luhansk (also known as Lugansk – a city in southeastern Ukraine), 2010. (Photo by X-F@ctor's bloG)

A young woman employee of North American Aviation Incorporated, working over the landing gear mechanism of a P-51 fighter plane, Inglewood, California, 1942. (Photo by Alfred T. Palmer/Buyenlarge/Getty Images)

Models present creation for the 7th Hosa Cup China Swimwear Design contest and Hosa Swimwear Trend fashion show on day five of China Fashion Week A/W 2011 on March 28, 2011 in Beijing, China (Photo by Feng Li/Getty Images)

Pope John Paul II (1920–2005) is shot by would-be assassin Mehmet Ali Agca in St Peter's Square, 13th May 1981. His attendants help him into his white jeep after the incident. (Photo by Keystone/Hulton Archive/Getty Images)

Models pose backstage ahead of the Gary Bigeni show during Rosemount Australian Fashion Week Spring/Summer 2011/12 at Overseas Passenger Terminal on May 4, 2011 in Sydney, Australia. (Photo by Matt King/Getty Images)

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)