A.較高壓力氣體 B.很高壓力氣體 C.較低壓力氣體 D.很低壓力氣體
A.8% B.5% C.3% D.2%
A.0.0001~0.001% B.0.001~0.01% C.0.01~0.1% D.0.1~1%