A hot air balloon competition called “Grudziadzkie Zawody Balonowe” is held in Lisie Katy, central-northern Poland, 14 May 2021. The compe​tition is held for the eighteenth time. (Photo by Tytus Zmijewski/EPA/EFE)

An internally displaced Afghan girl plays outside her shelter, amid the spread of the coronavirus disease (COVID-19), in Kabul, Afghanistan on May 7, 2020. (Photo by Mohammad Ismail/Reuters)

Mothers-to-be show their belly paintings in Hefei, east China's Anhui province on May 8, 2020. (Photo by Rex Features/Shutterstock/China Stringer Network)

Giraffes cross under the bridge of the Standard Gauge Railway (SGR) line inside the Nairobi National Park in Nairobi, Kenya, May 25, 2020. (Photo by Baz Ratner/Reuters)

People collect fish on the beach during the coronavirus disease (COVID-19) outbreak in Da Nang, Vietnam on May 6, 2020. (Photo by Kham via Reuters)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

Cardi B accepts the top rap song award for “I Like It” at the Billboard Music Awards on Wednesday, May 1, 2019, at the MGM Grand Garden Arena in Las Vegas. (Photo by Chris Pizzello/Invision/AP Photo)

A young woman takes pictures of the city with her mobile phone, from the glass-floor observation platform, in the Oriental Pearl Tower, in the financial district of Shanghai, on May 9, 2019. (Photo by Hector Retamal/AFP Photo)