A man exercises in the early morning on a hilltop overlooking Kabul, Afghanistan March 3, 2016. (Photo by Mohammad Ismail/Reuters)

Veteran racehorse Morestead models the world's first authentic Harris Tweed suit designed for a racing horse, which has been specially commissioned by William Hill to celebrate the opening of this year's Cheltenham Festival on March 15, 2016 in the U.K. (Photo by Joe Pepler/Rex Features/Shutterstock)

An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)

Meanwhile, over on Portobello beach, members of the Upsala circus take a stroll before their fringe debut, Ping-Pong Ball Effect in Edinburgh, England on August 1, 2017. (Photo by Murdo Macleod/The Guardian)

A woman wades through a flooded village in the eastern state of Bihar, India August 22, 2017. (Photo by Cathal McNaughton/Reuters)

A Kenya Wildlife Services (KWS) veterinarian and security personnel back away from a tranquilised black-Rhino calf August 30, 2017 after she appeared to prematurely overcome the sedative at the Nairobi National Park, during an identification-tagging excercise to ease quick identification of resident rhino during anti-poaching patrols. (Photo by Tony Karumba/AFP Photo)

Debutantes Amira Rayner, 19 (L) and Eliza Lewis, 17 (R) prepare at Boughton Monchelsea Place ahead of the Queen Charlotte's Ball on September 9, 2017 in Maidstone, England. (Photo by Jack Taylor/Getty Images)

South Vietnamese-born designer Quasar drives the six-foot long square-shaped plastic car he built and which is scheduled to be a hit with the young driving set, in Paris, June 23, 1967. The car can be driven at speeds of up to 60 mph (Photo by Michel Laurent/AP Photo)