No oxygen closed system 无氧密闭

no oxygen closed systems 无氧密闭体系

closed circuit oxygen system 闭式回路供氧系统

closed circuit oxygen equipment 闭路循环氧气设备

Closed-circuit oxygen self rescuers 密闭循环式氧气自我救生器

Closed oxygen cycle 闭合氧循环

closed oxygen cycling 密闭氧循环

closed oxygen-enriched 密闭富氧

closed type oxygen mask 气密式供氧面罩

oxygen enrichment closed-top blast furnace 富氧密闭鼓风炉