Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Policewomen take a picture inside a tunnel under the Chao Phraya river at a Mass Rapid Transit subway station in Bangkok, Thailand, December 14, 2015. (Photo by Athit Perawongmetha/Reuters)

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 girl sits on railway tracks at a makeshift camp for refugees and migrants at the Greek-Macedonian border near the village of Idomeni, Greece, March 19, 2016. (Photo by Alkis Konstantinidis/Reuters)

1st Place in Wildlife: A male orangutan peers from behind a tree while crossing a river in Borneo, Indonesia. (Photo by Jayaprakash Joghee Bojan/National Geographic Nature Photographer of the Year contest 2017)

Mature woman lying on bed, rear view. (Photo by Andersen Ross/Getty Images)

Fighters Feather “The Hammer” Hadden (L) and Allie “Babydoll” Parks compete during “Lingerie Fighting Championships 21: Naughty 'n Nice” at the Robinson Rancheria Resort & Casino on June 18, 2016 in Nice, California. Hadden won the bout. (Photo by Ethan Miller/Getty Images for LFC)