A protesting student runs past a burning bus off campus outside the University of the Witwatersrand in Johannesburg, South Africa on Monday, October 10, 2016. Tear gas and water cannon were fired as hundreds of students protested at the university amid a bitter national dispute with university managers and the government over demonstrators' demands for free education, forcing student into the neighbouring city streets. (Photo by AP Photo)

A girl smiles as her hair is blown by a strong wind in the Chinatown area in Yokohama, near Tokyo, Friday, January 27, 2017. (Photo by Koji Sasahara/AP Photo)

This picture taken on February 16, 2017 in Fangshan village in China's coastal province Fujians, shows a villager performing the “eating flowers” ritual. Villagers in eastern China have a unique way of washing away the taint of evil spirits – by bathing in a shower of scorching sparks. (Photo by Johannes Eisele/AFP Photo)

In this April 20, 2017 photo, a woman is aided by fellow demonstrators after falling, overcome by tear gas, during anti-government protests in Caracas, Venezuela. Tens of thousands of protesters asking for the resignation of President Nicolas Maduro flooded the streets again, one day after three people were killed and hundreds arrested in the biggest anti-government demonstrations in years. (Photo by Ariana Cubillos/AP Photo)

Two biplanes of the Team Breitling cross during a training flight prior the AIR14 air show in Payerne, Switzerland, August 29, 2014. (Photo by Peter Schneider/EPA)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

A competitor shows her tattoos at the MBK Tattoo Contest in a shopping mall in Bangkok October 23, 2014. (Photo by Athit Perawongmetha/Reuters)

A sales woman of a fish shop shows king crabs to a customer and negotiates the price in Noryangjin Fish Market is seen on August 1, 2015 in Seoul, South Korea. Noryangjin Fish Market was established in 1927 as Gyeongseong Susan in Jung-gu near Seoul Station and moved to its current location in 1971. (Photo by Shin Woong-jae/The Washington Post)