Students run at the guide of a teacher during an emergency drill in Xiyou Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. A drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Du Yu)

Students run during an emergency drill in Xiyou Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. The drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Du Yu)

Students run during an emergency drill in Xiyou Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. A drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Du Yu)

Students run during an emergency drill in Xiyou Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. A drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Du Yu)

Students run during an emergency drill in Huangshan Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. A drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Liu Junxi)

Students hide themselves under desks during an emergency drill in Huangshan Road Primary School in Hefei, capital of east China's Anhui Province, May 9, 2016. A drill was held on Monday at the school to improve the students' reaction against accidents. (Xinhua/Liu Junxi)