Common ontology languages. construction principles and construction methods were summarized. It was considered that constructing coal mine safety ontology should adopt OWL-DL language and the construction method of cyclic acquisition method or seven-step method. Current research status of the coal mine safety ontology was analyzed from aspects of coal mine digging and coal mine disast... https://www.ealisboa.com/best-flash-Nightstick-TWM-850XL-Tactical-Weapon-Mounted-Light-limited-super/