A boy runs past one of the exhibits during the Dinosaurs exhibition in Belgrade, Serbia, Thursday, August 21, 2014. “Dino Park” has opened at Belgrade's Kalemegdan Fortress. (Photo by Darko Vojinovic/AP Photo)

Two young boys kneel on stools on either side of a round table as one uses a match to this the other's cigarette, November 12, 1928. (Photo by FPG/Getty Images)

The British Breitling Wingwalkers, Danielle Hughes and Emily Guilding, soar above the Palm Jumeirah in Dubai at 1,500 feet (460 meters) in excess of 100mp/h, ahead of their Dubai debut performance at the 2014 UIM Skydive Dubai XCAT World Powerboating Series, on Saturday, 13th December 2014. The British team is the only aerobatic formation display team who employ full time wingwalkers and fly their two Breitling-liveried 1930's Boeing Stearman bi-planes at Air Shows and major sporting events around the world. (Photo by Katsuhiko Tokunaga/Breitling via AP Images)

To mark the occasion of International Women' s Day on March 8, 2018 AFP presents a series of photos depicting women performing roles or working in professions more traditionally held by men. Here: Professional wrestler Cristal (Crystal) poses for a photograph in her trainig place on February 09, 2018 in Mexico city, Mexico. (Photo by Omar Torres/AFP Photo)

Liu Chunxia, a supporter of Xu Zhiyong, one of China's most prominent rights advocates, is detained by policemen while she gathers with other supporters nearby a court where Xu's trial is being held in Beijing January 22, 2014. When dozens of activists unfurled banners across the country last March and April calling for officials to disclose their assets, they did so at the urging of one of China's most prominent rights advocates, Xu Zhiyong. Xu, 40, stands trial on Wednesday on a charge of “gathering a crowd to disturb public order” punishable by up to five years in prison. His case will almost certainly spark fresh criticism from Western governments over Beijing's crackdown on dissent. (Photo by Kim Kyung-Hoon/Reuters)

Malaysia's Ann Osman puts in her mouth guard before her mixed martial arts (MMA) ONE Championship fight against Egypt's Walaa Abbas in Kuala Lumpur, March 13, 2015. Osman is the first female Muslim MMA fighter to compete at the top level of the sport. (Photo by Olivia Harris/Reuters)

A Turkana tribeswoman reacts after an accidental fire of a shelter in Turkana settlement in Ilemi Triangle, Kenya, July 15, 2019. The Ilemi Triangle, a disputed sliver of land along the border with Ethiopia and South Sudan, is the northernmost tip of Turkana, Kenya's poorest county. A series of deadly clashes between the Turkana community and other ethnic groups that they said had crossed from South Sudan have put people on edge, to the point of posting lookouts. (Photo by Goran Tomasevic/Reuters)

“Liu Bolin is an artist born in China’s Shandong province in 1973, and he earned his Bachelor of Fine Arts from the Shandong College of Arts in 1995 and his Master of Fine Arts from the Central Academy of Fine Arts in Beijing in 2001. His work has been exhibited in museums around the world. Also known as “The Invisible Man”, Liu Bolin's most popular works are from his “Hiding in the City” series; photographic works that began as performance art in 2005”. – Wikipedia. (Photo by Reuters/China Daily)