An indigenous woman participates in a parade called "International Indigenous Beauty" during the first World Games for Indigenous Peoples in Palmas, Brazil, October 24, 2015. Billed as the indigenous Olympics, the games are expected to attract nearly 2,000 athletes from dozens of Brazilian ethnicities, as well as from such far-flung nations as Ethiopia and New Zealand. (Photo by Ueslei Marcelino/Reuters)

An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

Soldiers use electronic sensors to search for missing firefighters under a line of fire trucks caught in massive gas explosions in Kaohsiung, Taiwan, Friday, August 1, 2014. A series of underground explosions about midnight Thursday and early Friday ripped through Taiwan's second-largest city, killing scores of people, Taiwan's National Fire Agency said Friday. (Photo by Wally Santana/AP Photo)

People take pictures of the Tribute in Light while it is illuminated next to the Statue of Liberty (C), One World Trade Center and the Empire State Building during events marking the 14th anniversary of the 9/11 attacks on the World Trade Center in New York September 11, 2015. (Photo by Eduardo Munoz/Reuters)

A woman shields her face from the sun as she rides her scooter in Ahmedabad, India May 20, 2016. (Photo by Amit Dave/Reuters)

A woman receives a bouquet made of vegetables and flowers, priced at 238RMB, from a delivery staff of a florist outside an office building on Valentine's Day in Beijing, China, February 14, 2017. (Photo by Jason Lee/Reuters)

A mahout bathes his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India May 21, 2017. (Photo by Amit Dave/Reuters)

A general view of atmosphere at the annual VOLT Festival in Sopron, 208 kms west of Budapest, Hungary on June 30, 2017. (Photo by Sandor Csudai/Rockstar Photographers)