Pumps and fine filters are arranged _____ with one as standby.A.in duplicateB.in doubleC.a

The ship’s generator broke down, and the pumps had

听力原文：Hello! How are you？（15)A．Fine, thank you.B．And you？C．How are you？

Gear pumps are of positive displacement type pumps because they discharge a near constant

The globe valve has a bulbous body, housing a valve seat and screw down plug or disc arran

The various pumps and lines are _____ to some extent so that each pump can act as an alter

Katherine: Linda! I haven seen you for ages. How are you? Linda: Fine. And you? Katherin