单项选择题
A.G=3600P水银+ΔθcB.G=3600P水银-ΔθcC.G=3600P水银/(Δθc)D.G=Δθc/(3600P水银)
A.10~20B.20~25C.30~40D.30~50
A.两B.三C.四D.五