單項選擇題The internal part of the boiler, if found (), has to be chemically washed by yard.

A.deformed
B.rusted
C.cracked
D.scaled


您可能感興趣的試卷

你可能感興趣的試題

1.單項選擇題Centrifugal pumps can be designed with a number of impellers () to attain a high final delivery pressure.

A.in series
B.in parallel
C.either A or B
D.None of the above is tree

2.單項選擇題

Which of the following pumps are self-priming, and can deal with liquid from a level below the pump: ()
(1)reciprocating
(2)vane
(3)gear

A.(1)only
B.(1)and(2)
C.(2)and(3)
D.(1),(2)and(3)

5.單項選擇題Air chambers are usually fitted to reciprocating pumps in order to ().

A.increase discharge pressure
B.increase suction vacuum
C.develop pulsation flow
D.keep a steady rate of flow