Rays from the rising sun shine through the foliage of trees as fog covers the ground near the Guckler Karoly Observatory in Budapest, Hungary, 02 January 2017. (Photo by Balazs Mohai/EPA)

View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

An opposition activist clashes with the police during a march against Venezuelan President Nicolas Maduro held on May Day, in Caracas on May 1, 2017. Security forces in riot vans blocked off central Caracas Monday as Venezuela braced for pro- and anti- government May Day protests one month after a wave of deadly political unrest erupted. (Photo by Federico Parra/AFP Photo)

An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

Filipino firemen extinguish a burning vehicle during an earthquake preparedness drill in Makati city, south of Manila, Philippines, 22 June 2016. Thousands of people participated in the Metro Manila earthquake drill to prepare residents of nearly 12 million for a feared magnitude-7.2 quake that could kill thousands and displace millions, Emerson Carlos head of the Metropolitan Manila Development Authority (MMDA) said. Philippines sits on the Pacific Ring of Fire, an area prone to seismic shifts that spark earthquakes and volcanic activity. (Photo by Francis R. Malasig/EPA)

Rascal, and her brother Petey, were abandoned as pups near the railroad tracks in Union County, Arkansas. She is a pit bull cross and approximately 6 months old, in Arkansas, United States. These canine portraits will make any dog lover's day – and they're helping to get sheltered pups adopted at the same time. Kind-hearted photographer Tammy Swarek came up with the idea of dressing up rescue dogs to draw attention to their stories and help potential owners personally connect with them. (Photo by Tammy Swarek/Barcroft Images)

Billy Robinson, from Galax, Va., rides Gentleman Jim during the Professional Bull Riders Buck Off, in New York's Madison Square Garden, Saturday, January 17, 2015. The top 35 bull riders compete during the PBR event, returning to New York for the ninth consecutive year. (Photo by Richard Drew/AP Photo)

A box of 36 coloured pencils as photographed in a studio with an illustrative price tag of $115 (US dollars), equivalent to the Bs. 725 (bolivars) that it costs on average to purchase in Caracas at the official exchange rate of 6.3 bolivars per dollar, in Caracas September 29, 2014. Venezuela's economic crisis has led to some shocking and surreal price distortions that hit people's buying power dramatically. (Photo by Carlos Garcia Rawlins/Reuters)