A heavy，thick-walled tube，usually steel，used between the drill pipe and the bit in the drill stem to weight the bit in order to improve its performance is called a（）.

A fishing vessel displaying the lights shown is（）.

A fire has broken out on the stern of your vessel. You should maneuver your vessel so the wind （）.

A hand held instrument used to measure distances between objects and the ship is a（）.

An obstruction on a helodeck is any object that might present a hazard to the（）.

How could lashing gear used aboard Ro-Ro vessels be stowed when not in use? （）

A safe fuel system must（）.

A fire pump may be used for other purposes if（）.

For the purposes of cargo oil containment，the fixed container under the manifold of an eight-inch loading line must hold a minimum of（）.

A large valve，usually installed above the ram preventers，that forms a seal in the annular space between the pipe and wellbore or，if no pipe is present，on the wellbore itself is called the（）.