A visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)

Angel Hall, 22, (C) and Bri Artis, 21, (R) dance in a silent disco on the fourth and final day of the Firefly Music Festival in Dover, Delaware on June 17, 2018. (Photo by Mark Makela/Reuters)

Racegoers in attendance on Ladies Day at Ascot Racecourse on June 21, 2018 in Ascot, England. Ladies Day is the biggest day in the racing calendar and brings with it all the glitz and glamour as those attending don their best outfits. Ascot Racecourse is steeped in Royal history, first founded by Queen Anne in 1711, with the first race in her honour held on August 11, 1711. This year’s Royal Ascot began Tuesday, June 19, with races every day until Saturday, June 23. (Photo by South West News Service)

A model poses with a crocodile at Chinchorro Banks, Mexico on June 21, 2018. These crocs had a lot to smile about – sporting huge toothy grins as they posed with stunning models in incredible underwater snaps. The brave models held their breath as they came face to face with the magnificent predators during the daring shoot. Photographer Ken Kiefer took a two hour boat ride to reach the carnivorous crocs at Chinchorro Banks, Mexico, along with his wife and model, Kimber and model, Melodie Trevino. (Photo by Ken Kiefer/Caters News Agency)

Animal rights activists protest against the use of animal leather in fashion businness, a few days before the fashion week opening in Milan, Italy, 16 September 2018. (Photo by Matteo Bazzi/EPA/EFE)

Tourists take photos from a panoramic viewing deck on Victoria Peak in Hong Kong, China, 26 January 2019. Hong Kong has been ranked the world's freest economy by the Heritage Foundation, a conservative research and educational institution based in Washington, for the 25th consecutive year, but the researchers also said the judiciary had become less effective. (Photo by Jerome Favre/EPA/EFE)

Soldiers on exercise in Kenya. The image, by Sergeant Dek Traylor, is among the section winners in the UK Army Photographic Competition 2018. (Photo by Sergeant Dek Traylor/PA Wire Press Association)

Mackenzie Brown from the USA warms up on stage prior the final ofthe 47th Prix de Lausanne in Lausanne, Switzerland, 09 February 2019. Launched in 1973, the Prix de Lausanne is an international dance competition for young dancers. The best dancers will be awarded with scholarships granting free tuition in a world-renowned dance school or dance company. (Photo by Valentin Flauraud/EPA/EFE)