Members of the Al-Baraa bin Malek batallion, part of the Free Syria Army's Al-Fatah brigade, duck to the ground as they pull a man (R) who was shot by a sniper twice in the Bustan al-Basha district of the northern city of Aleppo on October 20, 2012. (Photo by Javier Manzano/AFP Photo)

Chinese paramilitary guards monitoring passengers as they head to their train to travel to their hometowns for the “Spring Festival” or Lunar New Year at Nantong Railway Station in Jiangsu province, near Shanghai Travellers taking part in the world' s largest annual human migration must be home by January 27 to usher in the new year on January 28. (Photo by AFP Photo/Stringer)

St Andrews University students skinny dip in the sea as May Day celebrations in St Andrews, Scotland on April 30, 2017. Hundreds of revellers ditched their clothes and bravely jumped into the bitterly cold North Sea. (Photo by Alamy Stock Photos)

The Paddington Bear balloon floats down Central Park West during the 90th annual Macy's Thanksgiving Day Parade on November 24, 2016 in New York. (Photo by Kena Betancur/AFP Photo)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

A young man “painting” the Eiffel Tower. (Photo by Keystone/Getty Images). 9th May 1970

Hopeful models together after their casting call for the 2008 for the L'Oreal Melbourne Fashion Festival at the Prahran Town Hall on January 23, 2008 in Melbourne, Australia. (Photo by Kristian Dowling/Getty Images)