In this photograph taken on Thursday, November 20, 2014, bud tenders Maxwell Bradford, back left, and Emma Attolini display buds in the shape of Christmas trees that are on sale for the holiday season in a recreational marijuana shop in northwest Denver. The nascent marijuana industry in Colorado is targeting holiday shoppers with special deals much like traditional retailers offer. (Photo by David Zalubowski/AP Photo)

Pro-Russian activists attack policemen guarding the burned trade union building in the southern Ukrainian city of Odessa on May 3, 2014. More than 30 people were killed in a “criminal” blaze in Ukraine's southern city of Odessa, as violence spread across the country during the bloodiest day since Kiev's Western-backed government took power. Ukraine's interior ministry said at least 31 people had died in the fire Friday, with local media reporting that pro-Russian militants were believed to have been in the burning building at the time. (Photo by Anatolii Stepanov/AFP Photo)

In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

“On the Li River near Xingping in China, Cormorant fishermen work the waterways before dawn amidst the spectacular limestone towers of the Karst landscape. The birds are trained to fetch fish from the inky depths but not swallow them. The fisherman accepts the fish from the birds who dive back for more. Here, still before dawn, the fisherman and his birds head for home”. (Photo and caption by Neville Jones/2014 Sony World Photography Awards)

Medical staff celebrate after all patients were discharged at a temporary hospital set up to treat people with the COVID-19 coronavirus in Wuhan in China's central Hubei province on March 9, 2020. China closed most of its makeshift hospitals for coronavirus patients, some schools reopened and Disney resort staff went back to work on March 9 as normality slowly returns to the country after weeks battling the epidemic. (Photo by AFP Photo/China Stringer Network)

People wear face masks while participating in the annual Memorial Day Parade on May 25, 2020 in the Staten Island borough of New York City. Dozens of cars and nearly 100 members of the patriotic motorcycle group Rolling Thunder joined the event. This year’s parade was diminished in size and in person-to-person contact due to the coronavirus outbreak. Across the country, events honoring the nation’s veterans have been cancelled or scaled back as America continues to experience high numbers of deaths and new cases of COVID-19. (Photo by Spencer Platt/Getty Images)

A man with an American flag on his back and a Biden/Harris campaign flag rides an electronic skateboard through Black Lives Matter Plaza in front of the White House on Election Day, November 3, 2020 in Washington, DC. This year's historic presidential election between President Donald Trump, the incumbent, and Democratic nominee Joe Biden begins to come to a close even though final results are not expected for days to come as states take longer to count historic levels of mail-in ballots. (Photo by Samuel Corum/Getty Images)

Andreyka, a 10-month-old female bear cub, plays with Rommi, an Alaskan malamute, at the Siberian Zoo in the settlement of Listvyanka, Irkutsk Region, Russia on December 9, 2020. The bear cub, which was found in a weak condition earlier this year, now play-fights with the Alaskan malamute, who adopted her and has seen three generations of bear cubs brought up in the Siberian zoo and released back into the wild. (Photo by Yuri Novikov/Reuters)