单项选择题
A.斜前方B.正上方C.斜上方D.正前方
A.2000Pa,2800Pa,1000PaB.2000Pa,2800Pa,1500PaC.2000Pa,2500Pa,1500PaD.3000Pa,2800Pa,1000Pa
A.JFB.JYC.JSD.JZ
A.灶前阀B.楼房附近燃气管道总阀C.热水器阀D.燃气表前阀
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