（）about 20 sq.m to be sand-blasted.

单项选择题A pumproom is suspected of accumulating gases after a ventilation machinery breakdown. Where should the combustible gas indicator case be placed when testing the pumproom atmosphere for combustible gases?（）.

A.In the lower level of the pumproom
B.In the middle level of the pumproom
C.In the upper level of the pumproom
D.On the deck outside the pumproom

单项选择题A partial deck in a hold is called a(n)（）.

A.weather deck
B.orlop deck
C.shelter deck
D.main deck

单项选择题A device used to tighten up remaining slack in wire rope when you are making up to a tow in inland waters is a（）.

A.tripping line
B.tripping bracket
C.norman pin
D.steamboat ratchet

单项选择题A bridle for an ocean tow consists of（）.

A.two chains of equal length
B.a single nylon pendant rove through a heavy ring free to move on the pendant
C.two long legs of wire rope shackled to a fishplate
D.a single length of heavy chain with both ends secured on deck to welded pad eyes

单项选择题A bollard is found on the（）.

A.beach
B.deck
C.pier
D.towed vessel