单项选择题
A.bar securing a cargo port B.centerline vertical bulkhead C.deep beam D.spanner stay
A spreader bar is used to（）.A.increase the lifting capa...
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
A spark arrestor（）.A.keeps sparks from falling into an ...
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
A single fitting installed in a pipeline that either bl...
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
