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單項(xiàng)選擇題

Auxiliary machinery covers everything onboard except （）.

A.main engines
B.main boilers
C.pipes and fittings
D.A and B

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單項(xiàng)選擇題

A （）, sometimes called filters, is a device designed to prevent the passage of unwanted solids into the system.

A.steam trap
B.check valve
C.separator
D.strainer

單項(xiàng)選擇題

To maintain the down stream pressure within defined limits over a range of flow and despite any changes in supply pressure, （） is fitted.

A.a check valve
B.a gate valve
C.a pressure reducing valve
D.a quick closing valve

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