A.小于或等于0.002MPa B.小于或等于0.005MPa C.小于或等于0.006MPa D.小于或等于0.004MPa
A.性質(zhì) B.壓力 C.氣源 D.用途
A.1%~10% B.3%~20% C.4%~70% D.6%~75%