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)
A handout photo made available by TeideLab shows an image composed of 200 pictures that shows the lightning activity between 3 am and 7am during a storm in Izana, Tenerife, Canary Islands, Spain, 27 October 2019. Over 2,000 lighting strikes fell mostly over Tenerife island last 26 October during a strong storm. (Photo by Daniel López/EPA/EFE/TeideLab)
Robots made by local enthusiasts and employees of an automobile repair workshop are seen during installation works on the outskirts of the rebel-controlled city of Donetsk, Ukraine, November 26, 2020. According to creators, who plan to open a robotics engineering park, 13-metre and 6-metre-high sculptures featuring transformer robots were made of waste metal including car components and weigh about 4 and 2 tonnes respectively. (Photo by Alexander Ermochenko/Reuters)
In a photo taken on June 5, 2017 a traffic security officer stands on duty at an intersection in Pyongyang. Officially known as traffic security officers but universally referred to as traffic ladies, they are chosen for their looks in a society that remains traditionalist in many respects. They must leave the role if they marry, and have a finite shelf-life, with compulsory retirement looming at just 26. (Photo by Ed Jones/AFP Photo)
A United States Air Force (USAF) F-15 fighter jet travels at low altitude through the “Mach Loop” series of valleys near Dolgellau, north Wales on June 26, 2018. The Mach Loop valleys, situated between Dolgellau and Machynlleth, are regularly used by the military for operational low flying training which can take place as low as 76 metres from the nearest terrain. The USAF regularly use the loop to practice low-altitude flight, which confuses radar systems. (Photo by Oli Scarff/AFP Photo)
A woman sticks out her tongue as she shops at the Quinta Crespo street market in downtown Caracas, Venezuela, Saturday, January 26, 2019. The country's political showdown moves to the United Nations Saturday where a Security Council meeting called by the United States will pit backers of President Nicolas Maduro against the Trump administration and supporters of the country's self-declared interim leader Juan Guaido. (Photo by Rodrigo Abd/AP Photo)
Tourists take photos from a panoramic viewing deck on Victoria Peak in Hong Kong, China, 26 January 2019. Hong Kong has been ranked the world's freest economy by the Heritage Foundation, a conservative research and educational institution based in Washington, for the 25th consecutive year, but the researchers also said the judiciary had become less effective. (Photo by Jerome Favre/EPA/EFE)