Sara Takanashi of Japan, Maja Vtic from Slovenia and Germany's Carina Vogt (R-L) prepare for a training session of the women's Individual normal hill HS100 ski jumping at the Nordic World Ski Championships in Falun February 18, 2015. (Photo by Kai Pfaffenbach/Reuters)

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

Peru, Iquitos. Restaurant in Bellavista, an area by the Amazon on April 2005. (Photo by Jean-Claude Coutausse)

A woman is led aside as her partner is detained by Ukrainian security forces for being aggressive at an army checkpoint in the southeastern port city of Mariupol, on May 11, 2014. Residents’ attitudes appear to have hardened considerably with the deaths of dozens of pro-Russian activists in the city of Odessa this month and with reports that troops fired at a crowd in Mariupol last week. (Photo by Marko Djurica/Reuters)

A Maasai warrior makes the high jump, in which athletes must touch a high line with the top of their heads, at the annual Maasai Olympics in the Sidai Oleng Wildlife Sanctuary near to Mt. Kilimanjaro, in southern Kenya, Saturday, December 13, 2014. Maasai men and women from the Amboseli and Tsavo region compete for medals and prizes in the event which aims for a sports competition of Maasai skills such as running, jumping, and throwing, to replace lion-hunting as the traditional warrior activity. (Photo by Ben Curtis/AP Photo)

An Indian woman wrapped in a shawl travels with others on a bullock cart on a cold day at Jhansi district, in Bundelkhand, India, Monday, December 29, 2014. Most parts of north India Monday continued to shiver under biting cold with the mercury dipping several notches. (Photo by Rajesh Kumar Singh/AP Photo)

A mother reacts as she pleads with police to allow her daughter to pass a checkpoint for cancer treatment after she arrived from Hubei province at the Jiujiang Yangtze River Bridge in Jiujiang, China, February 1, 2020. (Photo by Thomas Peter/Reuters)

A patient solves a rubik's cube at a temporary hospital converted from “Wuhan Livingroom” in central China's Hubei Province on February 10, 2020. In face of the outbreak of the novel coronavirus pneumonia epidemic, Wuhan authorities have transformed public venues such as exhibition centers and gymnasiums into temporary hospitals. The hospitals have a large capacity of treating patients with mild symptoms and play an important role in isolating the source of infection and cutting off the routes of infection during epidemic prevention. The first batch of patients was hospitalized on Feb. 5. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)