A.500kPa B.450kPa C.550kPa D.480kPa
A.(7±1)英寸汞柱 B.(8±1)英寸汞柱 C.(9±1)英寸汞柱 D.(10±1)英寸汞柱
A.2min15s+20s B.3min15s+20s C.5min45s+20s D.1min15s+20s