A man in a wartime uniform, poses for a photo on an abandoned tank at a beach, ahead of the 60th anniversary of Second Taiwan Straits Crisis against China, in Kinmen, Taiwan on August 19, 2018. (Photo by Tyrone Siu/Reuters)

Young children at a Bristol, Great Britain health centre unsure of the benefits of sun-lamps and the special glasses that must be worn, July 1948. The health centre was part of the newly introduced free National Health Service. (Photo by Popperfoto/Getty Images)

In this April 1, 2002, file photo, Mike Cole, of Jenkintown, Pa., right, performs a kick-flip over a trash can with his skateboard as tourists pose for photos in front of artist Robert Indiana's sculpture in John F. Kennedy Plaza, also known as Love Park, in Philadelphia. Granite slabs from Philadelphia's famed Love Park, a skateboarding mecca though for a long stretch an illegal one, are being shipped in 2017 to the city of Malmo, Sweden, nearly 4,000 miles away, for use in construction of a skate park there. (Photo by Douglas Bovitt/AP Photo)

Advanced Space Suit Engineer at NASA Kristine Davis wears the xEMU prototype space suit for the next astronaut to the moon by 2024, during its presentation at NASA headquarters in Washington, U.S., October 15, 2019. (Photo by Carlos Jasso/Reuters)

A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)

LiLou the therapy pig stands in front of a departures board at San Francisco International Airport in San Francisco, California, U.S. October 4, 2019. (Photo by Jane Ross/Reuters)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

Revellers gather for the start of the Annual SantaCon Bar Crawl at Father Duffy Square, a section of Times Square, on December 14, 2019, in New York City. SantCon is an event where people make donations to charitable causes and dress up as a Christmas character and visit bars around the city. (Photo by Steven Ferdman/Getty Images)