A woman strikes a police truck with her hand during a protest march in Santiago, Chile, Thursday, April 16, 2015. Thousands of students marched through the streets of Chile's capital to protest recent corruption scandals and to complain about delays in a promised education overhaul. While it was largely peaceful, violence broke out at the end when hooded protesters threw rocks and gasoline bombs at police. (Photo by Luis Hidalgo/AP Photo)

Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

A student runs for cover as riot police clash with students during a demonstration on February 29, 2012 in Barcelona, Spain. Student associations have called upon 120,000 students to strike in protest against education cuts recently announced by the Catalan government. (Photo by David Ramos/Getty Images)

Skeleton bodypainting in Chimbu tribe. Village Mindima, Simbu (a Highlands Region province in Papua New Guinea), September 14, 2009. (Photo by Rita Willaert; Source: Flickr)

Students take part in a fashion and design entrance examination at Hubei Institute of fine Arts on February 28, 2011 in Wuhan, Hubei Province of China. 202 students took part in the exam and only 24, (10 percent) of them will be enrolled in Hubei Institute of fine Arts. (Photo by ChinaFotoPress/Getty Images). WUHAN, CHINA – FEBRUARY 28

Students from St Andrew's University indulge in a tradition of covering themselves with foam to honour the “academic family” on October 20, 2014, in St Andrews, Scotland. Every November the “raisin weekend” which is held in the university's Lower College Lawn, is celebrated and a gift of raisins (now foam) is traditionally given by first year students to their elders as a thank you for their guidance and in exchange they receive a receipt in Latin. (Photo by Jeff J. Mitchell/Getty Images)

A protestor gestures during clashes with police during protests against planned fuel price hikes on March 27, 2012 in Jakarta, Indonesia. Thousands of Indonesians students in big cities all over the county gathered to protest the governments plans to increase the price of subsidized fuel by 30 percent. The Indonesian parliament is currently debating the fuel hikes which would go into effect March 25, 2012 if approved. (Photo by Ulet Ifansasti/Getty Images)