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)

Tuvalu Beneath the Rising Tide by Sean Gallagher, Tuvalu. Changing environments prize: Fallen trees lie on a beach as the waves from the Funafuti lagoon in Tuvalu lap around them. Land erosion has always been a problem for the South Pacific country but problems are intensifying as sea levels rise. Rising seas are on the verge of completely submerging the tiny archipelago’s islands. (Photo by Sean Gallagher/CIWEM Environmental Photographer of the Year 2019)

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)

The town hall with the Mangia tower is seen in Siena, central Italy, January 29, 2016. (Photo by Max Rossi/Reuters)

“Oak Sunrise” by professional photographer Alan Price has won the International Garden Photographer of the Year, “Celebrating Our Oaks” competition, run in partnership with Action Oak. Action Oak is a campaign to protect the UK’s oak trees from threats including pests and diseases. (Photo by Alan Price/IGOTY)

A woman with high heels walks on a sidewalk which is renovated on August 10, 2017 in downtown Moscow, as the city continues with preparations for next year's FIFA World Cup. (Photo by Mladen Antonov/AFP Photo)

A duck salesman parades his stock to commuters at a busy station in Dhaka, Bangladesh on May 23, 2018. (Photo by Nazmul Hasan Khan/Caters News Agency)