A.5~10mmHg(0.7~1.3kPa)
B.10~20mmHg(1.3~2.6kPa)
C.20~30mmHg(2.6~4.0kPa)
D.30~40mmHg(4.0~5.3kPa)
E.40~50mmHg(5.3~6.7kPa)