In this Wednesday, September 17, 2014 photo, the sun shines over a field of sunflowers in Walkill, N.Y. (Photo by John DeSanto/AP Photo/Times Herlad-Record)

Unnati, 6 years old, at home with his sister Ishika, 4 years old, in the Mahamai Ka Bagh neighborhood. Unnati was born to parents contaminated by a carcinogenic and mutagenic water supply. This year marks the 31st anniversary of the 1984 Union Carbide gas tragedy that killed thousands of citizens of Bhopal within 72 hours and has gone on to claim thousands more as a result of the polluted environment. (Photo by Giles Clarke/Getty Images)

People dressed in costumes have a break while marching during the Vijanera Festival, in the small village of Silio, northern Spain, Sunday, January 3, 2016. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly coloured clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Francisco Seco/AP Photo)

Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)

People are reflected in a shop window as they walk along a street in a shopping district in Tokyo, Japan June 25, 2015. (Photo by Thomas Peter/Reuters)

Syrian refugee girl Nur El-Huda, 9, shows a drawing of her home in Syria, in her classroom in Yayladagi refugee camp in Hatay province near the Turkish-Syrian border, Turkey, December 16, 2015. Syria's conflict has left hundreds of thousands dead, pushed millions more into exile, and had a profound effect on children who lost their homes or got caught up in the bloodletting. The drawings of young refugees living in Turkey show their memories of home and hopes for its future. The pictures also point to the mental scars borne by 2.3 million Syrian refugees living in Turkey, more than half of them children. (Photo by Umit Bektas/Reuters)

A Muslim bride waits for the start of a mass marriage ceremony in Mumbai, India, January 27, 2016. A total of 12 Muslim couples took their wedding vows during the mass marriage ceremony organised by a Muslim voluntary organisation, organisers said. (Photo by Danish Siddiqui/Reuters)

A street in the Cuban capital, Havana, is home to 12 sets of twins, ranging from toddlers to senior citizens. Some say it could be something in the water. Others point to a tree with mystical significance for locals. And maybe it's just chance. Photo: In this September 29, 2013 photo, nine-year-old twin sisters Camila, left, and Carla Rodriguez pose for a portrait along their street in Havana, Cuba. 12 sets of twins live along two consecutive blocks in western Havana, ranging in age from newborns to senior citizens. “We love living on this block because we have twin friends”, said Carla. (Photo by Ramon Espinosa/AP Photo)