Riot policemen launch tears gas canisters during clashes with coca growers from Yungas in La Paz, Bolivia February 21, 2017. (Photo by David Mercado/Reuters)

A member of the Tinstix of Dynamite aerobatics team flies in front of a wall of fire during the Australian International Airshow in Melbourne on March 5, 2017. The annual event sees 180,000 visitors over the 3-day public event held at the Avalon Airfield some 80kms south-west of Melbourne. (Photo by Mal Fairclough/AFP Photo)

A woman carries earthen pots to fill them with drinking water on a hot summer day, on the outskirts of Ajmer, Rajasthan, India April 25, 2017. (Photo by Himanshu Sharma/Reuters)

People enjoying the races on a wet day at Chester Racecourse on May 12, 2017 in Chester, England. (Photo by Alan Crowhurst/Getty Images)

Women wearing sunglasses pose for a group photo at a park in Beijing in 1980. (Photo by Reuters/China Daily)

1st prize in the People Observed Portraits Stories category. Carla Kogelman, the Netherlands. The photo shows Hannah and Alena, two sisters living in the rural village of Merkenbrechts, Austria. (Photo by Carla Kogelman/World Press Photo)

Sunday night, Lauren Watts searches for her dog in Mayflower, Arkansas., after a tornado struck the town. (Photo by Benjamin Krain/The Arkansas Democrat-Gazette)

This photo released by the Cleveland Animal Protective League shows Lurleen, the nursing mother and Noland the puppy snuggling up Wednesday, June 19, 2013, in Cleveland. Lurleen already is caring for four newborn kittens and now is nursing the orphaned week-old pit bull puppy in Cleveland. (Photo by AP Photo/Cleveland Animal Protective League)