Clean air standards referred to as “Grade D” apply to compressed air for use in().
A.high pressure fluid accumulators
B.driving air-powered plunger pumps
C.filling open-circuit breathing systems
D.bladder-type accumulators
参考答案:C
Clean air standards referred to as “Grade D” apply to compressed air for use in().
A.high pressure fluid accumulators
B.driving air-powered plunger pumps
C.filling open-circuit breathing systems
D.bladder-type accumulators
参考答案:C