All ships（）suspected infectious disease on board should radio information to Port Health Officer.

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

A.Apply ice-cold compress and renew every 4 hours
B.Commence artificial respiration immediately
C.Give enema
D.Pass catheter into bladder

单项选择题A safe fuel system must（）.

A.prevent engine overheating
B.have proper air/gasoline fuel mixture ratio
C.be liquid- and vapor-tight
D.supply sufficient air to the intake manifold

单项选择题A large vessel is equipped with a controllable pitch propeller. Which statement is TRUE?（）

A.When dead in the water，it is often difficult to find the neutral position and slight headway or sternway may result
B.When going directly from full ahead to full astern，there is complete steering control
C.When the vessel has headway and the propeller is in neutral，there is no effect on rudder control
D.When maneuvering in port，full ahead or astern power can usually be obtained without changing shaft RPM

单项选择题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.annular blowout preventer
B.annulus
C.accumulator
D.automatic choke

单项选择题A large metallic device，mounted directly in the piping (usually located at the dock near the point where the vapor hose is attached)，designed to prevent the passage of a rapidly moving flame through the piping is called a（）.

A.flame arrestor
B.flame screen
C.detonation arrestor
D.detonation blocker