For a ship not on an international voyage，an approved substitute for an impulse projected rocket-type line throwing appliance is a（）.

单项选择题Any vessel in need of carrying out deck washing must be（）by the department concerned beforehand.

A.requested
B.allowed
C.approved
D.inquired

单项选择题An obstruction on a helideck is any object that might present a hazard to the（）.

A.rotor blades and landing gear
B.unloading of passengers
C.loading of cargo
D.pilot's visibility

单项选择题AN ILLNESS PREFERABLY OF AN INFECTIOUS NATURE SEIZING MORE THAN TWO PERSONS ON BOARD AT THE SAME TIME defines（）.

A.Disease of Crew
B.Crew illness
C.Group illness
D.Mass disease

单项选择题Aboard a survival craft，ether can be used to（）.

A.start the engine in cold weather
B.aid in helping personnel breathe
C.prime the sprinkler system
D.prime the air supply

单项选择题A towline should be fastened to（）.

A.the chocks at the bow of a towed vessel
B.the most forward，centermost point of a towed vessel such asa sturdy bow rail
C.the mast of a towed sailboat
D.a secure fitting near the bow of the towed vessel