单项选择题
A.30 B.40 C.50 D.20
A.540Kpa,15Kpa B.600Kpa,10Kpa C.640Kpa,15Kpa D.700Kpa,10Kpa
A.1100 B.1200 C.1300 D.1400
A.0.5 B.1 C.1.5 D.2.5
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