A.1mm/10PaB.2mm/20PaC.3mm/30PaD.4mm/40Pa
A.正負(fù)壓小B.正負(fù)壓大C.正壓小,負(fù)壓大D.正壓大,負(fù)壓小
A.0.7B.0.8C.0.9D.1.0