A.15%-20% B.25%-33% C.33%-40% D.40%-50% E.>50%
A.PaO265mmHg,PCO240mmHg B.PaO255mmHg,PCO245mmHg C.PaO250mmHg,PCO260mmHg D.PaO285mmHg,PCO255mmHg E.PaO275mmHg,PCO230mmHg