A Polisario fighter sits on a rock at a forward base on the outskirts of Tifariti, Western Sahara, September 9, 2016. At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. (Photo by Zohra Bensemra/Reuters)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)

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)

In this January 3, 2018 photo several female Gelada baboons, also known as bleeding-heart baboons, cuddle with their youngs in order to keep warm at the Wilhelma zoo in Stuttgart, Germany. (Photo by Sebastian Gollnow/DPA via AP Photo)

Chileans watch the sky with special suits prior to a total solar eclipse on July 2, 2019 in Paiguano, Chile. Around 25,0000 tourists arrived to Paiguano, a small town of around 1,000 inhabitants in the Elqui Valley, 650 km away Santiago. This is the only Earth's total solar eclipse of 2019 and the first one since 2017. From this point, the sun will fully disappear for around two minutes. It is best visible from a stripe in the South Pacific, Chile and Argentina. (Photo by Marcelo Hernandez/Getty Images)

This photo taken on November 4, 2019 shows people taking part in a fish catching competition in a paddy field in Leishan county in China's southwestern Guizhou province, to celebrate the new year festival Miao people. (Photo by AFP Photo/China Stringer Network)

Prince Philip, the Duke of Edinburgh meets members of the cast of “Chicago” during a visit to the Adelphi Theatre in this March 4, 1999 file photo in London, England. (Photo by Anwar Hussein/Getty Images)

A view through mist shows the Kirk of Saint Mary Magdalene in Primorsk, Leningrad Region, Russia on March 24, 2019. (Photo by Anton Vaganov/Reuters)