Train attendants take part in a parade training as they visit the national flag guard during a patriotic education event ahead of the 90th anniversary of the founding of the Chinese People's Liberation Army (PLA) in Beijing, China July 25, 2017. (Photo by Reuters/China Stringer Network)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

In this November 30, 2017 photo, Douglas scoops up mud from the bottom of the polluted Guaire River, in search of gold and anything valuable he can sell, in Caracas, Venezuela. Some stretches of the river smell of sewer while others emit a toxic odor of fuel, a stench that stays in ones nose for hours after leaving the water. (Photo by Ariana Cubillos/AP Photo)

A guest proposes to his companion as they arrive for the screening of “Mektoub, My Love: Intermezzo” during the 72nd annual Cannes Film Festival, in Cannes, France, 23 May 2019. The movie is presented in the Official Competition of the festival which runs from 14 to 25 May. (Photo by Julien Warnand/EPA/EFE)

Women perform the Chilean protest song about rape culture, “A rapist in your path”, during a protest march marking International Women's Day, in Lima, Peru. Saturday, March 7, 2020. March 8th has been sponsored by the United Nations since 1975 as International Women's Day, celebrating women's achievements and aiming to further their rights. Marches and protests are held across the globe with calls for a more gender-balanced world to mark the day. (Photo by Rodrigo Abd/AP Photo)

A girl wears a mask to help protect herself from the new coronavirus jogs as the sun sets over the Mediterranean Sea coastline, in Beirut, Lebanon, Tuesday, April 14, 2020. (Photo by Hassan Ammar/AP Photo)

Members of the Israeli Mermaids Community bathe in the sea with a mermaid tails at the beachfront in Bat Yam, near Tel Aviv, Israel, Saturday, May 23, 2020. Members of the Israeli mermaid community gathered at the beachfront to mark the beginning of the bathing season. (Photo by Oded Balilty/AP Photo)

The aerobatic demonstration team of the Italian Air Force, the Frecce Tricolori (“Tricolor Arrows”), fly over the Basilica of Saint Mary of Health as they perform as part of a nationwide tour to show unity and solidarity following the outbreak of the coronavirus disease (COVID-19), in Venice, Italy, May 29, 2020. (Photo by Manuel Silvestri/Reuters)