A tribesman loyal to the Houthi movement carries his rifle as he leaves a gathering held to show support for the group, in Yemen's capital Sanaa December 15, 2015. (Photo by Khaled Abdullah/Reuters)

A colourful sky before sunrise on Whitley Bay beach on December 21, 2015, as December could be the mildest across a large part of England since records began more than 350 years ago, forecasters have said. (Photo by Owen Humphreys/PA Wire)

An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

An isolated five-floor building stands in the middle of a new road on November 22, 2012 in Wenling, Zhejiang Province of China. Zhejiang Province of China. 67-year-old Luo Baogen and his 65-year-old wife from Xiazhangyang village still live in the half-demolished residential building, because they are dissatisfied with the relocation compensation. The road, which leads to the Wenling Railway Station, has not been put into use. (Photo by China Foto Press)

7th August 1941: A Soviet sniper targets the enemy with the telescopic sight on his rifle.

Tourists watch illuminated snow sculptures during the 31st Harbin Sun Island International Snow Sculpture Art Exposition on January 4, 2019 in Harbin, Heilongjiang Province of China. The 31st Sun Island International Snow Sculpture Art Exposition officially opened to public on December 29. (Photo by VCG/VCG via Getty Images)

Chinese artist Zhou Jie takes a nap on an unfinished iron wire bed, one of her sculpture works, after lunch as a friend of hers looks on at Beijing Now Art Gallery, in Beijing August 11, 2014. Zhou started her art project titled “36 Days” on August 9, in which she would live inside an exhibition hall with an unfinished iron wire bed, some iron wire sculptures in the shape of stuffed animal dolls, a certain amount of food and her mobile phone, for 36 days. The entire process is open to visitors and she may also interact with them, according to Zhou. (Photo by Jason Lee/Reuters)

Medical workers walk by a police robot at the Wuhan Tianhe International Airport after travel restrictions to leave Wuhan, the capital of Hubei province and China's epicentre of the novel coronavirus disease (COVID-19) outbreak, were lifted, April 8, 2020. (Photo by Aly Song/Reuters)