The world-famous sprinter Usain Bolt, 30, took a break from the track to celebrate Carnival as revellers doused each other with paint in Trinidad and Tobago on February 26, 2017. (Photo by David Wears/Splash News and Pictures)

In this April 20, 2017 photo, a woman is aided by fellow demonstrators after falling, overcome by tear gas, during anti-government protests in Caracas, Venezuela. Tens of thousands of protesters asking for the resignation of President Nicolas Maduro flooded the streets again, one day after three people were killed and hundreds arrested in the biggest anti-government demonstrations in years. (Photo by Ariana Cubillos/AP Photo)

Cuban girls dressed as nurses and a lizard wait for their turn to dance during a visit by the Gay Men's Chorus of Washington in Havana July 13, 2015. The choir made its first appearance on July 12, 2015 in Cuba as part of a tour that will include a dozen concerts in the context of the restoration of relations between the island and the United States. (Photo by Enrique de la Osa/Reuters)

A man washes his horse as a woman bathes her son at concrete water pens under a flyover in a slum area in Kolkata, India October 21, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

A four-year-old dog Nika stands next to an image of Cuba's revolutionary hero Ernesto “Che” Guevara in front of a flooded street in Havana, January 23, 2016. Havana's seafront Malecon continued to be slammed by massive waves that flooded parts of the seaside city on Saturday. As a result, Havana was confronting flooding as a cold front passes through the Caribbean island. The giant waves began washing up onto shore during sunrise. The waves have been accompanied by winds passing through at a speed between 35 and 50 km (21 to 31 miles) per hour. (Photo by Alexandre Meneghini/Reuters)

According to the U.S. government, Moldova, one of the poorest countries in Europe, depends on about $1.6 billion annually sent back from the roughly one million Moldovans who left for work in in Europe, Russia, and other former Soviet Bloc countries. Photographer Myriam Meloni went to Moldova to document what she refers to as “social orphans” – children whose parents have emigrated to another country in search of a job and a better future for their families. Here: Lulia is seen washing dishes in her grandmother's house, where she lives. (Photo by Myriam Meloni)

A doll in a children's gas mask is seen amongst beds at a kindergarten in the abandoned city of Pripyat near the Chernobyl nuclear power plant in Ukraine on March 28, 2016. Deadly radiation still spews from Chernobyl 30 years after the worst nuclear meltdown in history, as a newly built giant arch is pulled into place to cover the stricken reactor for the next century. (Photo by Gleb Garanich/Reuters)