单项选择题
(A)氮气系统压力可能不足 (B)用抽真空法较易发现有无泄漏 (C)吸附系统较大接点多 (D)氮气会使吸附剂中毒
(A)0.35~0.88Mpa (B)0.35~0.60Mpa (C)0.15~0.35Mpa (D)0.15~0.88Mpa
(A)0.35Mpa (B)0.60Mpa (C)0.88Mpa (D)0.15Mpa