An old toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. The exhibition focuses on how the toilet has changed our daily lives and discovers what the most environment-friendly and ideal toilet is. (Photo by Keith Tsuji/Getty Images)

In this Sunday, March 2, 2014 photo, animal barber Mohamed Mahmoud shaves a customer's initials onto the rump of a donkey in Cairo, Egypt. Clients typically request for regular trims to keep animals cool in the summer, initials in English letters, and patterns – but sometimes they give Mahmoud full creative license. (Photo by Maya Alleruzzo/AP Photo)

General view of the monument to memory of soldiers who liberated the city of Knin – in Knin, Croatia on November 10, 2014. Across the former Yugoslavia stand giant monuments to a state that no longer exists, once visited and celebrated during public holidays such as Republic Day on November 29, marking the creation of socialist Yugoslavia. Many are now neglected or ignored, aging symbols of a joint state forged during World War Two but torn apart by nationalism half a century later. Republic Day is no longer marked in any of the seven independent states that emerged from its ashes. (Photo by Antonio Bronic/Reuters)

A boy walks past boats docked at the entrance gate of the fishermen's village in the El Max area of the Mediterranean city of Alexandria September 12, 2014. El Max, where hundreds of boats dart through the canals, has been called the “Venice of Egypt” for its waterways and relaxed atmosphere. Its fishermen, however, worry about how they will make ends meet on meagre earnings they say are being reduced further by polluted waters that are making fishing more difficult. While the government has tried to fix the state's bloated finances by cutting subsidies and reining in spending, some argue the reforms hurt Egypt's most vulnerable who have long relied on a generous system of fuel and food subsidies to supplement low incomes. (Photo by Amr Abdallah Dalsh/Reuters)

A boy covers his head with fallen leaves as he enjoys a stroll with his family in a park in downtown Frankfurt, Germany, November 6, 2016. (Photo by Kai Pfaffenbach/Reuters)

A herd of wildebeest cross the skyline against the fading light in Masai Mara, Kenya, 25 August 2017. Stunning sunset photos silhouette Africa’s wildlife against streaks of orange and red sky. In August, German photographer Ingo Gerlach was on safari in the Masai Mara when he convinced his safari guide to stop and take in the sunset. The wildlife photographer was rewarded with his patience by an eye-catching sunset, which cast Africa’s wildlife into dark shadows against the vibrant skies. (Photo by Ingo Gerlach/Barcroft Images)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)