Soldiers try to attach the balloon to their car, June 1944. (Photo by Jared Enos/Mediadrumworld.com)

Activists in a clay outfits at the Rathausmarkt during the art protest campaign “1000 Gestalten” (lit 1000 figures), for more solidarity and political participation, in Hamburg, Germany, 17 June 2017. In a two-hour show hundreds of actors took part in a creative public appeal for more humanity and self-responsibility ahead of the upcoming G20 summit. The G20 economic summit takes place in Hamburg July 7-8. (Photo by Lukas Barth-Tuttas/DPA/Alamy Live News)

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

Clash of the storms, New Mexico, US by Camelia Czuchnicki. “A clash between two storm cells in New Mexico, US, each with its own rotating updraft. The curved striations of the oldest noticeable against the new bubbling convection of the newer. It was a fantastic sight to watch and it’s the rarity of such scenes that keep drawing me back to the US Plains each year”. (Photo by Camelia Czuchnicki/Weather Photographer of the Year 2016)

A young Shiite Muslim child participates in a Muharram procession in Ahmadabad, India, Sunday, October 9, 2016. (Photo by Ajit Solanki/AP Photo)

A horse grazes on railway tracks near the old train station on the the Northeast railroad (Ferrovia do Nordeste) in the city of Missao Velha, Ceara state, northeastern Brazil, October 25, 2016. (Photo by Ueslei Marcelino/Reuters)

Carolina Gutierrez (center L), 17, and Neuil Valdez, 18, use mobile phones to connect to the internet at a hotspot in downtown Havana, Cuba, December 12, 2016. (Photo by Alexandre Meneghini/Reuters)