Children react after what activists said was shelling by forces loyal to Syria's President Bashar al-Assad near the Syrian Arab Red Crescent center in the Douma neighborhood of Damascus May 6, 2015. (Photo by Bassam Khabieh/Reuters)

A member of the Eton public school O.T.C. (Officers Training Corps) practising shouting out orders during a training session, 20th January 1940. (Photo by Hulton Archive/Getty Images)

Saraa Mutawkil (R), 18, practises boxing at Al Rabie club in Omdurman May 10, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)

India: A sweeper cleans the side of a road near a replica of the Eiffel Tower amid heavy fog in the early morning in the northern Indian city of Chandigarh January 18, 2010. (Photo by Ajay Verma/Reuters)

A topless Femen activist jumps on the car carrying former IMF chief Dominique Strauss-Kahn (not seen) as he arrives for his trial in Lille, northern France, on February 10, 2015. Three topless women from the protest group Femen jumped on the car of Dominique Strauss-Kahn as the former IMF chief arrived to testify at his trial for “aggravated pimping”. With slogans scrawled on their half-naked bodies and hurling insults at the car, the three protesters were quickly rounded up by police as the car entered an underground parking area. (Photo by Denis Charlet/AFP Photo)

Frenchman Georges Speicher drinks as he starts riding down the Col de l'Aubisque during the 18th stage of the Tour de France between Tarbes and Pau. on July 17, 1933. Speicher finished second beaten by Spanish winner Learco Guerra to retain his overall leader's yellox jersey on his way to winning the Tour de France. (Photo by France Presse Voir/AFP Photo)

Aerial view of tourists in life vests and rubber rafts in the Grand Canyon of western Henan, Sanmenxia, China on August 5, 2017. (Photo by Imaginechina/Rex Features/Shutterstock)

A stork-billed kingfisher (Pelargopsis capensis) is seen perched on a tree during monsoon rain on July 25, 2016 in Bintan, Indonesia. The stork-billed kingfisher is a tree species which is widely but sparsely distributed in the tropical Indian subcontinent and Southeast Asia, from India to Indonesia. This kingfisher is resident throughout its range. It is very large, measuring 35 to 38 cm (14 to 15 in) in length. The adult has a green back, blue wings and tail, and grey head. (Photo by Sijori Images/Barcroft Images)