United States Air Force Academy graduates cheer as the United States Air Force Thunderbirds fly over the graduation for the Class of 2021 at Falcon Stadium on May 26, 2021 in Colorado Springs, Colorado. Chairman of the Joint Chiefs of Staff General Mark A. Milley gave the commencement address to the 1,019 graduates from the academy. (Photo by Michael Ciaglo/Getty Images)

Christmas baubles shaped as Santa Clauses wearing protective masks are pictured amid the coronavirus disease (COVID-19) pandemic in Eichenau, Germany, November 26, 2021. (Photo by Michaela Rehle/Reuters)

A woman moves a sandbag along a flooded road in the aftermath of the heaviest recorded rainfall in Zhengzhou in central China's Henan province on Saturday, July 24, 2021. Rescuers used bulldozers and rubber boats to move residents out of flooded neighborhoods in central China on Saturday after torrential rains killed at least 56 people. (Photo by Dake Kang/AP Photo)

A woman dressed as the Wizard of Oz’s Dorothy walks her dog dressed as the Cowardly Lion as they attend the annual Congressional Dog Costume Parade on Capitol Hill in Washington, DC, on October 27, 2021. (Photo by Jim Watson/AFP Photo)

A man helps a woman through a flooded neighbourhood in the aftermath of Cyclone Kenneth, in Pemba, Mozambique, April 28, 2019. (Photo by Mike Hutchings/Reuters)

A woman poses for a photograph in front of a 3D painting at HK 3D Museum in Hong Kong June 26, 2014. (Photo by Tyrone Siu/Reuters)

Photographers gather to take pictures of pilot Andre Borschberg (C) ahead of the take off of Solar Impulse 2-a solar powered plane- in Nanjing, China, May 31, 2015. The world's largest solar-powered airplane, Solar Impulse 2, took off from eastern China's Nanjing on Sunday to continue its round-the-world voyage. The Swiss-made plane left Nanjing's Lukou International Airport at 2:39 in the early morning, with former fighter pilot Borschberg at the controls alone for the entire 8,200-kilometer flight from Nanjing to Hawaii, the toughest leg of its marathon adventure. (Photo by Reuters/Solar Impulse)

Colorado Gov. John Hickenlooper shows off his socks--one with Democratic presidential candidate Bernie Sanders and the other with Republican candidate Donald Trump – before entering his former brewpub for a book signing event to mark the release of his autobiography Thursday, May 26, 2016, in Denver. Hickenlooper, who is term-limited, is doing book talk rounds this week, reviving speculation that he is positioning himself to join Hillary Clinton's presidential campaign ticket. (Photo by David Zalubowski/AP Photo)