A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)

An Iraqi boy sits next to cats for sale at the Ghazl Market in central Baghdad on November 20, 2020. (Photo by Ahmad Al-Rubaye/AFP Photo)

Yan Zhengming (R), 94, and his wife Zhou Suqing (C), 90, attend their wedding ceremony at their home, on the 70th anniversary of their marriage, in Quxian county of Dazhou, Sichuan province, China, May 15, 2015. The wedding, organized by local charity groups, was a long-time wish of veteran of the World War Two Yan, who married Zhou 70 years ago, but could not afford to have a wedding ceremony, local media reported. (Photo by Reuters/Stringer)

A commuter holding his shoes rides on a tricyle through a flooded street, caused by a heavy downpour brought about by the southwest moonson, in Manila, Philippines on August 2, 2019. (Photo by Ted Aljibe/AFP Photo)

A performer dressed as Empress Huang of the China's Forbidden City takes part in a musical performance at a shopping mall in Kuala Lumpur on January 22, 2017 as part of the upcoming Lunar New Year celebrations marking the Year of the Rooster. (Photo by Manan Vatsyayana/AFP Photo)

A woman holds an elderly woman on her back to cross a flooded street after a heavy rain in Shenyang, Liaoning province on July 14, 2017. (Photo by Fred Dufour/AFP Photo)

People walk passed sculptures by Chinese artist Minjun Yue on a street outside a museum in Beijing, China on July 5, 2018. (Photo by Nicolas Asfouri/AFP Photo)

An undated handout picture made available on 29 April 2016 by the Toronga Zoo shows a baby echidna making a remarkable recovery after being attacked by chickens in a family's backyard at the Taronga Zoo in Sydney, Australia. (Photo by EPA/Taronga Zoo)