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 camel is seen as he is being brought for the foot surgery at the Dubai Camel Hospital in Dubai, UAE, December 11, 2017. (Photo by Satish Kumar/Reuters)

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)

British fashion model Twiggy plays around on the bumper cars at the Bertram Mills Circus in London, England on January 10, 1967. (Photo by AP Photo)

Meropidae are seen on a rock in Van in Turkey on March 03, 2018. (Photo by Ali Ihsan Ozturk/Anadolu Agency/Getty Images)

Afghan female police cadets are seen during their graduation ceremony at Sivas Police Vocational Center Directorate in Sivas, Turkey on March 13, 2018. (Photo by Serhat Zafer/Anadolu Agency/Getty Images)

Women dressed as a rabbit and a fox, who pose for pictures with tourists, walk in central Kiev, Ukraine April 4, 2018. (Photo by Gleb Garanich/Reuters)

A woman holds newly designed Indonesia Rupiah banknotes after exchanging her old bills at a Bank Indonesia mobile bank in Jakarta, Indonesia December 19, 2016. (Photo by Fatima El-Kareem/Reuters)