A.bar securing a cargo portB.centerline vertical bulkhe……

单项选择题A spreader bar is used to（）.

A.increase the lifting capacity
B.increase the lifting radius
C.protect the slings
D.protect the upper part of a load

单项选择题A spark arrestor（）.

A.keeps sparks from falling into an open tank
B.secures covers on ullage openings
C.prevents sparks from getting out of an engine's exhaust system
D.grounds static electricity

单项选择题A single fitting installed in a pipeline that either blanks off the pipe or allows a full flow passage of a liquid through the pipe is referred to as a（）.

A.blind flange
B.pivot coupling
C.quick-release coupling
D.spectacle flange

单项选择题A ship crane which has been idle for a period of over six months shall be inspected to the same standards as a（）.

A.yearly inspection
B.quarterly inspection
C.monthly inspection
D.weekly inspection

单项选择题A sheepshank is used to（）.

A.keep a line from fraying
B.join lines of unequal size
C.stop off a line
D.shorten a line