A resident reacts as a health worker collects a swab sample to test for the Covid-19 coronavirus in Colombo on July 27, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty Images)

A general view of a royal wedding themed window display at Agent Provocateur in Pont Street, Chelsea on April 29, 2011 in London, England. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Adrian Murrell/Getty Images)

Ratko Mladic makes his first appearance at the International Criminal Tribunal on June 3, 2011 in The Hague, Netherlands. Ex-Bosnian Serb army leader Ratko Mladic will make his first appearance at The Hague war crimes tribunal after being declared fit to stand trial. Mladic was arrested a week ago after going into hiding for the past 16 years and is charged with atrocities committed during the Bosnian war. (Photo Serge Ligtenberg/Getty Images )

A visitor is reflected in a light installation at Mulberry Lights on Regent Street in London, UK on November 16, 2018. Visitors have fun taking selfies and posing with the colourful light installations. Mulberry Lights is a series of illuminating interactive experiences that celebrate how light, colour, shapes and people come together to create a modern British Christmas. (Photo by Imageplotter/Rex Features/Shutterstock)

A cleric and a woman pray behind a closed door of Masoume shrine in the city of Qom, some 80 miles (125 kilometers) south of the capital Tehran, Iran, Monday, March 16, 2020. On Monday, Iran closed the Masoume shrine, a major pilgrimage site in the city of Qom, the epicenter of the country's new coronavirus outbreak. Authorities were already restricting access and barring pilgrims from kissing or touching the shrine, but it had remained open. (Photo by AP Photo)

A man being tested for the COVID-19 novel coronavirus reacts as a medical worker takes a swab sample in Wuhan in China's central Hubei province on April 16, 2020. China has largely brought the coronavirus under control within its borders since the outbreak first emerged in the city of Wuhan late last year. (Photo by Hector Retamal/AFP Photo)

A fruit bat eats lettuce as it hangs from a rope during a behind the scenes interactive live stream from the Oakland Zoo on April 16, 2020 in Oakland, California. Since the Oakland Zoo has been closed to the public during the shelter in place, they are offering a subscription based service that will feature five weekly behind the scenes live streamed interactive programs that will feature animal keepers and their animals. Viewers are able to interact with the keepers by submitting questions to about the animals. (Photo by Justin Sullivan/Getty Images)