A towel with a print of the Nigerian naira is displayed for sale at a street market in the central business district in Nigeria's commercial capital Lagos February 4, 2016. (Photo by Akintunde Akinleye/Reuters)

Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)

Farmer Zhang Xianping rides his pig "Big Precious" during an interview with the media, in Zhangjiakou, Hebei province, China, November 2, 2015. Zhang, a pig breeder, instead of killing it, decided to keep the two-year-old "Big Precious" as pet when its weight reached 600 kg, according to local media. (Photo by Reuters/China Daily)

In this January 12, 2016 photo, an abandoned boat lies on the dried up lake bed of Lake Poopo, on the outskirts of Untavi, Bolivia. Drought caused by the recurrent El Nino meteorological phenomenon is considered the main driver of the lake's demise. Along with glacial melting, authorities say another factor is the diversion of water from Poopo's tributaries, mostly for mining but also for agriculture. (Photo by Juan Karita/AP Photo)

Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)

A doll forms part of a sculpture as part of an exhibit titled The Sea Isn't Made for Fish at Rio de Janeiro Federal University in Rio de Janeiro, Brazil, Monday, June 1, 2015. Art students have taken advantage of a material they have in endless supply trash to create an exhibition that aims to draw attention to the fetid state of the citys Guanabara Bay, where the Olympic sailing events are to be held next year. (AP Photo/Silvia Izquierdo)

Farmers herd a flock of ducks along a street towards a pond as residents drive next to them in Taizhou, Zhejiang province, June 17, 2012. (Photo by Reuters/China Daily)

“Hatem Moussa joined The Associated Press as a photojournalist in 1998. Since then, the Gaza City-based Moussa has covered repeated rounds of Israeli-Palestinian fighting in Gaza, including the wars of 2008-9, 2012 and 2014”. – Associated Press. Photo: A Palestinian youth jumps into the Mediterranean sea on the beach at the port of Gaza City, Gaza, Monday, August 27, 2012. (Photo by Hatem Moussa/AP Photo)