Tourists pose with pigeons in the flooded St. Mark's Square in Venice, on November 7, 2014. The high water, a combination of high tides and a strong Scirocco wind in the Adriatic Sea, stood at 110 centimeters early on November 7. The city has for years been wrestling with the problems posed by the threat of rising sea levels. (Photo by Olivier Morin/AFP Photo)

A woman takes a photograph of a sculpture titled “Couple Under an Umbrella, 2013” by Australian sculptor Ron Mueck during a preview of his exhibition at the Pinacoteca Museum in Sao Paulo November 19, 2014. (Photo by Nacho Doce/Reuters)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)

Dolly the Chihuahua dog dressed as Alice in Wonderland is photographed during an Alice in Wonderland and Charlie and the Chocolate Factory themed Furbabies Dog Pageant at Jodhpurs Riding School in Tockwith, North Yorkshire, Sunday September 6, 2020. (Photo by Danny Lawson/PA Wire via AP Photo)

Two visitors take pictures of autumn leaves at Rikugien Garden Tuesday, December 10, 2019, in the Bunkyo district of Tokyo. (Photo by Jae C. Hong/AP Photo)

Giant panda Ying Ying rests on a rock in its enclosure while a visitor takes a selfie at Ocean Park in Hong Kong, China, 24 September 2020. An An turned 35 in August. Giant pandas in the wild can live up to 20 years on average, while lifespans of those under human care can reach over 30 years. (Photo by Jerome Favre/EPA/EFE)

Operations & Exercises, 1st place. An RAF Voyager aircraft sits in the harsh winter weather at Mount Pleasant Complex, Falkland Islands, while personnel work to ensure the snow is cleared. (Photo by Sgt Andy Holmes/2020 RAF Photo Competition)

People train parrots during a parrot-training show held by Kuwaiti bird lovers in Jahra Governorate, Kuwait, December 7, 2020. (Photo by Xinhua News Agency/Rex Features/Shutterstock)