单项选择题
A.2.5kPa(250mmH2O) B.1.5kPa(150mmH2O) C.3.0kPa(300mmH2O) D.1.9kPa(190mmH2O) E.2.0kPa(200mmH2O)
A.0.5~1.0kPa(50~100mmH2O) B.0.7~2.0kPa(70~200mmH2O) C.1.0~1.5kPa(100~150mmH2O) D.0.8~2.1kPa(80~210mmH2O) E.1.0~2.5kPa(100~250mmH2O)