单项选择题
A.2200B.2240C.2350D.2400
A.4mm±1mmB.5mm±1mmC.6mm±1mmD.7mm±1mm
A.10cm2/gB.10cm3/gC.10cm2/kgD.10cm3/kg
A.60,0.1B.60,0.01C.50,0.1D.50,0.01
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