A.5-20cmH2O B.10-20cmH2O C.5-10cmH2O D.15-20cmH2O E.5-15cmH2O
A.0.1 B.0.5 C.1.0 D.1.5 E.2.0
A.400~500ml B.600~700ml C.800~1600ml D.1700~2400ml E.>2400ml