Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

Demonstrators protest during a rally against Venezuelan President Nicolas Maduro, in Caracas on April 19, 2017. Venezuela braced for rival demonstrations Wednesday for and against President Nicolas Maduro, whose push to tighten his grip on power has triggered waves of deadly unrest that have escalated the country' s political and economic crisis. (Photo by Juan Barreto/AFP Photo)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

An Indian soldier from the international peace keeping force (IPKF) instructs young Sri Lankan recruits in shooting, part of the training given to the citizen's volunteer force in the North-Eastern Sri Lankan city of Batticaloa, September 28, 1989. (Photo by Barbara Walton/AP Photo)

A model wears a creation during the presentation of Chanel Cruise collection in Paris, Wednesday, May 3, 2017. Chanel is hosting its itinerant resort show, destined for glamorous women who sojourn on cruise ships. (Photo by Francois Mori/AP Photo)

A nurse at St. Joseph's Hospital wears a unique mask as the hospital celebrates the release of a COVID-19 patient after 45 days in their care during the outbreak of the coronavirus disease (COVID-19) in Orange, California, U.S., May 5, 2020. (Photo by Mike Blake/Reuters)

Afghan vendors sort out oranges for sale at a wholesale market in the Bati kot district in Nangarhar province, Afghanistan, 04 December 2020. The orange fruit floods markets across Afghanistan due to bumper crop in the winter season. Oranges are rich in vitamin C, which may reduce severity of the common cold. (Photo by Ghulamullah Habibi/EPA/EFE)

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)