Particularly some unknown around the state-owned mine goaf is one of the most important damage source to impact on the mine safety.
2
安全危害源不仅存在于食品的原料、加工、贮藏、流通等环节,更重要的来源之一是环境污染。
Safety hazards source presents at not only raw materials, processing, storage, distribution and other sectors, and more importantly, one of the sources is environmental pollution.
Check valves are important valves in pipeline system. Falty selection of these valves, for many years, have been the harmful source of increasing surge in pipeline system.