An exam invigilator looks over pupils sitting an A level exa [Getty Images]

UNITED KINGDOM - JUNE 12: An exam invigilator looks over pupils sitting an A level exam at Maidstone Grammar school, Maidstone, U.K., on Friday, June 12, 2009. Pupils who take part in several extra-curricular activities tend to perform better in exams, research by the Independent Schools Council suggests. (Photo by Chris Ratcliffe/Bloomberg via Getty Images)

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