In or der to e nsure normal teaching orde r, protecti ng students ' healt hy growt h, ensuri ng that national (property) is not lost , to prev ent or mi nimize the occurrence of safety acci dents, follow the "preve nt, rescue each ot her, ensure safety a nd re duce losses" principle, accordi ng to t he l ocal condit ions, make the ma nagement system. 1, the pri ncipal is t he responsi bility of s