A.大于等于30kV B.大于等于40kV C.大于等于50kV D.大于等于60kV
A.大于等于20kV B.大于等于25kV C.大于等于30kV D.大于等于35kV
A.小于等于7mL/L B.小于等于8mL/L C.小于等于9mL/L D.小于等于10mL/L