People look at a man, who residents said was killed by al Qaeda militants, hanging on a bridge in Yemen's southeastern city of Mukalla June 17, 2015. Al Qaeda militants in Yemen killed two alleged Saudi spies, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected U.S. drone strike. (Photo by Reuters/Stringer)

A veterinarian kisses an 8-month-old cat, wearing a prosthetic two-wheel device, at a veterinary hospital in Chongqing municipality, March 16, 2015. The cat's rear legs lost the abilty to walk after falling from the ninth to fifth floor of a building last November, its since undergone four major surgeries which included removing parts of its organs, local media reported. (Photo by Reuters/China Daily)

A boat commutes across the Mekong river in Phnom Penh on August 8, 2014. The Mekong is the world's twelth longest river running from the Tibetan Plateau through China's Yunnan province, Myanmar, Laos, Thailand, Cambodia and Vietnam. (Photo by Tang Chhin Sothy/AFP Photo)

People and sea-gulls bathe in the sea as the sun goes up with red colors in Stralsund close to the baltic sea island of Rügen, on early November 23, 2016. (Photo by Stefan Sauer/AFP Photo/DPA)

Britain's Princess Elizabeth clasps her hands in sympathy as Sergeant Jean Bayliss faints at her feet during an inspection of the guard of honour of the Women's Royal Army Corps at Shrewsbury Castle, Shropshire, on July 6, 1949. (Photo by AP Photo)

Two boys look out from the Mangueira slum towards the Maracana Stadium that is hosting the Rio's 2016 Summer Olympics opening ceremonies, in Rio de Janeiro, Brazil, Friday, August 5, 2016. (Photo by Leo Correa/AP Photo)

Belarusian ornithologist Vladimir Ivanovski, 72, stands on a tree as he builds an artificial nest for birds of prey from tree branches, in a marsh near the village of Kazyany, Belarus on October 20, 2019. (Photo by Vasily Fedosenko/Reuters)

Bathers brave the cold waters of the North Sea as they take part in the annual Boxing Day dip at Redcar Beach on December 26, 2019 in Redcar, England. The event attracts hundreds of people each year who take to the cold water wearing fancy dress as they help to raise money for a number of charities. (Photo by James Glossop/The Times)