Although the number of coal mine roof accidents and the number of deaths have dropped significantly, the overall proportion is still high, and roof accidents are still the main safety accidents in coal mines.
Although the number of coal mine roof accidents and the number of deaths have dropped significantly, but the overall proportion is still high, roofing accidents are still the main safety accidents in coal mines.
Although the number of coal mine roof accidents, the number of deaths have decreased significantly, but the overall proportion is still high, roof accidents are still the main safety accidents in coal mines.<br>