Snow covers roofs, streets and the Charles River following a winter blizzard in Boston, Massachusetts January 28, 2015. A powerful blizzard struck Boston and surrounding New England on Tuesday, leaving some 4.5 million people grappling with as much as three feet of snow and coastal flooding. (Photo by Brian Snyder/Reuters)

Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

A migrant smokes a cigarette as he waits among others to cross the Croatian border near the village of Berkasovo, Serbia October 19, 2015. Thousands of migrants clamoured to enter European Union member Croatia from Serbia on Monday after a night spent in the cold and mud of no-man's land, their passage west slowed by a Slovenian effort to impose limits on the flow to western Europe. (Photo by Marko Djurica/Reuters)

Women practice yoga during a performance on a glass bridge at the Shiniuzhai National Geo-park in Pingjiang county, Hunan province, China, November 5, 2015. About hundred yoga fans put on the show to promote the concept of green life and the idea of harmony between human and nature on Thursday, according to local media. (Photo by Reuters/China Daily)

Revellers celebrate New Year's Day in central Moscow, Russia, January 1, 2016. (Photo by Tatyana Makeyeva/Reuters)

Carlos Cure holds packets of corn flour made in Colombia as he poses for a picture at a stall that sells food and staple items at a market in La Fria, Venezuela, June 2, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

Women breastfeed their babies at an event promoting the freedom of mothers to breastfeed in public, during World Breastfeeding Week, at the Village Museum in Bucharest Romania, Saturday, August 6, 2016. (Photo by Andreea Alexandru/AP Photo)

Street vendors carry chickens for sale at Kawran Bazar in Dhaka, Bangladesh January 25, 2017. (Photo by Mohammad Ponir Hossain/Reuters)