In or der to e nsure normal teaching order, prote cting st ude nts ' healthy growth, e nsuring that national (property) is not lost, to preve nt or mi nimize the occurre nce of safety accide nts, foll ow the " prevent, rescue each ot her, ensure safety and reduce losses" pri nci ple, a ccordi ng to the local conditi ons, make t he manag ement system. 1, the principal i s the re sponsibility of sch