A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)

A group of children run into a fountain on the South Bank on August 1, 2011 in London, England. Temperatures in the capital reached around 27 degress today and are expected to hit 30 degrees by Wednesday. (Photo by Dan Kitwood/Getty Images)

A baby hippopotamus lies next to its mother on the first day it was presented to the public at the Zoo Berlin zoo on November 1, 2011 in Berlin, Germany. The baby hippo was born at the zoo on October 23. (Photo by Sean Gallup/Getty Images)

A sheep dressed in a jersey in the colors of the Colombian national soccer team is seen during a exhibition in Nobsa, Colombia June 1, 2014. The sheep is named Falcao, after the Colombian player. REUTERS/Jose Miguel Gomez

People sit near a fully loaded in Madama near the border with Lybia on January 1, 2015. French Defence Minister Jean-Yves Le Drian paid a surprise visit to northern Niger on January 1, to visit a base being built to combat the growing flow of weapons and jihadists from neighbouring Libya. Le Drian travelled from Chad to Madama, a desert outpost about 100 kilometres from Libya, where he saw in the New Year with troops at a French base. Madama is situated on the route used by jihadists and arms smugglers in southern Libya to reach northern Mali and Niger. (Photo by Dominique Faget/AFP Photo)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

Mary, 8-months-old female orphan elephant, drinks milk at Winga Baw Elephant Conservation Camp during the ceremony to mark World Elephant Day at Bago Region, Myanmar, 12 August 2017. Winga Baw Elephant Conservation Camp, 34-hectare former timber camp for logs located in Bago Region, currently has 14 elephants and was opened for recreation for locals as well as for tourists. World Elephant Day is marked annually on 12 August. (Photo by Lynn Bo Bo/EPA/EFE)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)