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單項(xiàng)選擇題

In the piping systems of a vessel，what type of valve gives the least resistance to fluid flow when fully open?（）.

A.Globe valve
B.Butterfly valve
C.Gate valve
D.Packless valve

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單項(xiàng)選擇題

In ship operations，hoisting and lowering pipe in and out of the drilled hole is the main function of the（）.

A.swivel
B.cathead spool
C.drawworks
D.stand pipe

單項(xiàng)選擇題

In ship construction，keel scantlings should be the greatest（）.

A.at each frame
B.amidships
C.one-third the distance from the bow
D.one-third the distance from the stern

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