A girl carries on her head a pile of dried shrubs she gathered for cooking and heating, in Kabul, Afghanistan November 18, 2015. (Photo by Omar Sobhani/Reuters)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)

A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)

In this picture made available Thursday July 11, 2013 a zoo-keeper presents three of twelve ferret babies at Eekholt Zoo in Grossenaspe, Germany, Wednesday July 10, 2013. The ferret babies were born May 25, 2013. (Photo by Markus Scholz/AP Photo/Dpa)

A man dressed as a zombie sits next to a woman on a park bench during the Sydney Zombie Walk on October 24, 2010 in Sydney, Australia. The Sydney Zombie Walk saw participants travel a route through the business district starting and culminating at Sydney's Hyde Park. (Photo by Brendon Thorne/Getty Images)

A rescuer saves a resident from a flooded area in Wuhan, Hubei Province, China, July 2, 2016. (Photo by Reuters/China Daily)

A little red flying fox dips a toe in a lake at the mouth of Katherine gorge in the Northern Territory, Nitmiluk national park, Australia on September 20, 2017. (Photo by Glenn Campbell/AAP)