Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)

In this Thursday, October 3, 2019 photo, a female black bear sleeps with its tongue out high up in a Ponderosa pine tree near Clark Fork School in the Rattlesnake neighborhood of Missoula, Mont. The bear's cub, not pictured, was snoozing on a nearby branch. (Photo by Tommy Martino/The Missoulian via AP Photo)

In this Tuesday, August 27, 2019, file photo, a climber stops to take pictures of clouds while climbing towards the summit of Mount Fuji to watch the sunrise, in Japan. (Photo by Jae C. Hong/AP Photo/File)

University students wearing Guy Fawkes masks pose for a photoshoot of a graduation ceremony to support anti-government protests at the Hong Kong Polytechnic University, in Hong Kong, China on October 30, 2019. (Photo by Tyrone Siu/Reuters)

A male Philippine eagle named Geothermica is seen in an exclosure at Jurong Bird Park in Singapore on November 27, 2019. Singapore unveiled two Philippine eagles at its main aviary November 27, the first breeding pair of the critically endangered raptors to be brought outside their native country as part of a conservation plan. (Photo by Roslan Rahman/AFP Photo)

Tokyo DisneySea at Urayasu, Chiba prefecture, is holding Christmas festivities each night until December 25, 2012. At neighboring Tokyo Disneyland, the Christmas Fantasy parade is held twice daily at the theme park. (Photo by Disneyland)

Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)