單項選擇題A frame with two，or sometimes four，arms through which are threaded the guidelines and which is used to keep the drill stem and bit in line with the center opening in the temporary guide base is the（）.

A.drill stem guide
B.guide frame
C.drill string frame
D.casing guide


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1.單項選擇題A flooded leg on a liftboat would adversely affect the vessel’s stability underway by（）.

A.increasing the righting moment
B.decreasing the vessel's displacement
C.increasing the reserve buoyancy
D.shifting the CG (center of gravity) off center

3.單項選擇題A fishing vessel displaying the lights shown is（）.

A.anchored
B.underway but not fishing
C.tending a small fishing boat
D.fishing by trawling

4.單項選擇題A fishing vessel casualty must be reported to the Coast Guard if it involves（）.

A.loss of life
B.an injury requiring only first aid
C.$(SA)10，000 in property damage
D.loss of equipment which doesn't reduce the vessel's maneuverability

5.單項選擇題A fire pump may be used for other purposes if（）.

A.the other services are run off a reducing station with a pressure gage
B.one of the required pumps is kept available for use on the fire main system at all times
C.no relief valves are installed
D.all of the above conditions are met