A.hard ironB.soft ironC.vertical iron onlyD.horizontal ……

单项选择题Permanent magnetism is caused by（）.

A.operation of electrical equipment and generators on board ship
B.the earth's magnetic field affecting the ship's hard iron during construction
C.the horizontal component of the earth's magnetic field acting on the horizontal soft iron
D.the vertical component of the earth's magnetic field acting on the vertical soft iron

单项选择题It is not necessary to declare（）in the Health List.

A.Appendicitis
B.Cholera
C.Plague
D.Typhus fever

单项选择题It is not necessary to declare（）in MARITIME HEALTH DECLARATION.

A.Jaundice by fever
B.Acute skin rash or eruption with or without fever
C.Duodenitis

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

A.Drape along brackets
B.Leave in place while back loading cargo to save time
C.Hang vertically in the paint locker
D.All of the above

单项选择题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.three barrels
B.four barrels
C.six barrels
D.eight barrels