A.1~5cmH2O B.5~12cmH2O C.6~15cmH2O D.15~20cmH2O E.20~25cmH2O
A.1/2 B.1/3 C.2/3 D.3/4 E.2/5
A.800mL B.1000mL C.1200mL D.1400mL E.500mL