单项选择题
A.氮气B.氧气C.氢气D.惰性气体
A.0.1~0.2MPaB.0.22~0.39MPaC.0.14~0.49MPaD.0.25~0.45MPa
A.≥0.5MΩB.≤0.5MΩC.≥5MΩD.≤10MΩ