Two chimpanzees share a piece of watermelon at Taronga Zoo on December 23, 2010 in Sydney, Australia. (Photo by Rick Stevens/Taronga Zoo via Getty Images)

A lighting bolt flashes in the sky as U.S. Army M1A1 Abram tanks roll through the desert December 9, 2002 near the Iraqi border in Kuwait. (Photo by Joe Raedle/Getty Images)

Sri Lankan military personnel march during the country's 66th Independence Day celebrations in the central town of Kegalle, about 40 kms from the capital Colombo on February 4, 2014. Sri Lanka cemmemorates its independence from British rule on February 4, 1948. (Photo by Ishara S. Kodikara/AFP Photo)

Revellers celebrate “Ash Monday” by participating in a colourful “flour war”, a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, Greece, February 27, 2017. (Photo by Alkis Konstantinidis/Reuters)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

Fire fighters, emergency service vehicles and a helicopter in Moskovsky Prospekt at the entrance to Tekhnologichesky Institut station of the St Petersburg metro in the aftermath of an explosion which occurred in a train at 14:40 Moscow timeon April 3, 2017. (Photo by Peter Kovalev/TASS)

Actress Liv Tyler, 40, stripped in shots for the Triumph Essence's Autumn/Winter 2017 campaign in November, 2017. The Essence line is Triumph’s premium offering, with this season taking on the theme of “opulent Art Nouveau”, featuring designs in velvet embellished mesh, Leavers lace and silk satin. (Photo by Rankin/The Mega Agency)

A leg of a “diablito” frog (Oophaga sylvatica) is photographed in a laboratory at a laboratory in the zoo of Cali, Colombia, on July 19, 2019. Colombia is the second country with the largest number of amphibians in the world after Brazil. More than 40% of amphibian species worldwide are in danger of extinction. (Photo by Luis Robayo/AFP Photo)