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 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)

Students at the Cuba's National Ballet School (ENB) watch a class from outside the classroom in Havana, Cuba, October 12, 2016. Catherine Conley, the first American full-time student at Cuba's prestigious National Ballet School, hopes to gain an edge back home by learning the powerful Cuban style with its dazzling turns and jumps. (Photo by Alexandre Meneghini/Reuters)

A visitor views a human body specimen during the “Human Body's Wonder Scientific Travelling Exhibition” at the Haikou Gymnasium April 30, 2006 in Haikou of Hainan Province, China. The exhibition displays 13 complete real human body specimens and about 300 pieces of small samples, such as organs, skin, etc with the purpose to promote science and help people know more about their bodies. (Photo by China Photos/Getty Images)

A model poses with her bodypainting designed by bodypainting artist Arianna Barlini from Italy, in the 2016 World Bodypainting Festival, 2016 in Poertschach am Woerthersee, Austria. (Photo by Didier Messens/Getty Images)

Final preperations are made backstage during Graduate Fashion Week at Earls Court on June 6, 2011 in London, England. The event which began in 1991 showcases emerging talent from BA Graduate fashion design courses across the UK and includes exhibition stands and catwalk shows from around 50 universities. (Photo by Dan Kitwood/Getty Images)

Badminton School sixth form pupils (L-R) Lucy Warden, who got 3 A* and is off to study English at Durham, Sam Crumpton, who got 1 A* and 2 A's and is off to study to be a vet at Cambridge and Madeline Sunter, who got 2 A* and 1 B, and is off to study fashion at St. Martins, celebrate their A-level results on August 18, 2011 in Bristol, England. With another record year for A-level results, sixth-form students face a scramble for university places in the final year before tuition fees rise. According to the examination bodies the pass rate rose for the 29th successive year to hit 97.8 percent, while around one in 12 exams achieved the top A* grade. (Photo by Matt Cardy/Getty Images)