Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

Players perform during a game at the first Bubble Soccer tournament in Hitzkirch, near Lucerne, Switzerland, June 27, 2015. Bubble Soccer, also known as Zorb Soccer, is becoming increasingly popular around the world. The game is a recreation of playing soccer whilst encased in an inflated zorb which covers the players upper-body and head. (Photo by Urs Flueeler/EPA)

A conductor (C) collects fares from candy floss sellers as they travel in a tram to a marketplace early morning in Kolkata, India, December 23, 2015. (Photo by Rupak De Chowdhuri/Reuters)

These macro images by Alejandro Santillana are being showcased in the Insects Unlocked project at the University of Texas at Austin. Here: A female sweat bee. (Photo by Alejandro Santillana/Insects Unlocked/Cover Images)

A model of a ghost made from translucent fibreglass is lit from inside at Gem's (Wax Models) Ltd, in the Portobello Road area of west London. The ghost is due to go to the Capistrano Mission Museum in California, where tourists are told the legend of how he frightened a young Indian girl novice to death. 1st May 1965. (Photo by Chris Ware/Keystone Features)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

A snow leopard looks on from an inside of a cage, after being captured from the southern plains of Nepal and brought to the central zoo, which wildlife experts say is rare for the animal that is found in the higher altitude, in Kathmandu, Nepal on January 26, 2024. (Photo by Navesh Chitrakar/Reuters)

Atsushi Abe and Yumi Adachi from Japan perform in the synchronised swimming mixed duet technical routine preliminary at the Aquatics World Championships in Kazan, Russia July 25, 2015. (Photo by Michael Dalder/Reuters)