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單項選擇題

Limit switches are used on which davits?（）

A.Sheath-screw davits
B.Gravity davits
C.Radial davits
D.Quadrantal davits

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單項選擇題

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

單項選擇題

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

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