protective gas保护气体protectiveadj.保护的；防卫的protective coatings for the radiation[化] 防辐射线涂料Protective Headgear Used in Bicyclingprotective type of tortuous liability预防型侵权责任PROTECTIVE GROUPS IN ORGANIC SYNTHESIS基团保护Protective system false operation rate继电保护误动作率Protective helmets for vehicular users乘车安全帽protective goggles against ultraviolet防紫外线眼镜protective goggles against infra-red防红外线眼镜Protective Ensemble for USAR Operations操作现场防护标准protective layer of overflowing surface过流面防护层