A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

Three prostitutes lean out of a window in Santiago, Chile, in an attempt to entice customers inside, circa 1950. (Photo by Three Lions/Getty Images)

A giant sinkhole in Guatemala City, on May 31, 2010. More than 94,000 were evacuated as the storm buried homes under mud, swept away a highway bridge near Guatemala City and opened up several sinkholes in the capital. (Photo by Casa Presidencial/Reuters via The Atlantic)

Yan Zhengming (R), 94, and his wife Zhou Suqing (C), 90, attend their wedding ceremony at their home, on the 70th anniversary of their marriage, in Quxian county of Dazhou, Sichuan province, China, May 15, 2015. The wedding, organized by local charity groups, was a long-time wish of veteran of the World War Two Yan, who married Zhou 70 years ago, but could not afford to have a wedding ceremony, local media reported. (Photo by Reuters/Stringer)

Law enforcement officers stand, with some turning their backs, as New York City Mayor Bill de Blasio speaks on a monitor outside the funeral for NYPD officer Wenjian Liu in the Brooklyn borough of New York January 4, 2015. Tens of thousands of law enforcement officers from across the country gathered on Sunday for the funeral of the second of two New York City policemen killed last month in an ambush that galvanized critics of Mayor de Blasio. (Photo by Shannon Stapleton/Reuters)

Latefat Alao, 56, a ethnic Yoruba Muslim woman, waits for customers in front of her in Beere market in Ibadan, southwest Nigeria, January 29, 2015. Much of the grain and wheat traders like Alao sell comes from the north and Boko Haram's campaign has negatively affected farmers and food markets. Reuters photographer Akintunde Akinleye photographed Nigerians and asked them about their views on the elections as well as their hopes and concerns for the country. (Photo by Akintunde Akinleye/Reuters)

March 28, 1967. Egg Roll; A large bunny attracted the attention of children and their parents during the annual Easter egg roll Monday on the south lawn of the White House. The bunny was made by Fred Johansen, Silver Spring, Md. Nearly 17,000 youngsters and adults took part in the egg rolling. The President and Mrs. John-son were not at the festivities because they were in Camp David, Md. The tradition of egg rolling was begun in 1878 during the administration of Rutherford B. Hayes. (Photo by Minneapolis Star Tribune)

In this Monday, March 16, 2015 photo, Syrian refugee Samira Helal, 17, who is two months pregnant, poses for a portrait at inside her tent at an informal tented settlement near the Syrian border, on the outskirts of Mafraq, Jordan. Nearly 3.8 million Syrians have fled their country and are now registered as refugees, according to the U.N. Most face increasingly desperate circumstances. (Photo by Muhammed Muheisen/AP Photo)