JIUJIANG, CHINA - MARCH 12:  (CHINA OUT) A student sleeps with a book covering his face as sheets laid on the ground are aired in the sun at Jiujiang University on March 12, 2012 in Jiujiang, Jiangxi Province of China. After a long winter vacation returning Chinese students will air their sheets, duvets and clothes in the grounds of the halls of residence to help freshen them up.  (Photo by VCG/VCG via Getty Images)