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

After sending a message describing the symptoms of an ill crew member，you receive a message containing the code MRL. This means（）.

Permanent magnetism is found in（）.

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

It is not necessary to declare（）in the Health List.

Please supply 200 tons of fresh water（）my ship.

An inert gas system on a tanker should be used to（）.

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 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（）.

A helmsman receives the command “Right 15 degrees rudder.”The helmsman’s IMMEDIATE reply should be（）.