High school students cover themselves in bed sheets while learning what to do during a nuclear disaster in a drill in Shijiazhuang, Hebei province, on July 8, 2013. [Photo/CFP]
High school students practice lying on the ground face down during a duck-and-cover drill designed to educate them on how to protect themselves from an unexpected nuclear disaster in Shijiazhuang, Hebei province, on July 8, 2013. [Photo/CFP]