A contra-guide is a type of（）.

单项选择题A common means of connecting shots of anchor chain in the field is to use a（）.

A.sprocket
B.Kenter link
C.swivel
D.end shackle

单项选择题A chain stripper is used to（）.

A.prevent chain from clinging to the wildcat
B.clean the marine debris from the chain
C.flake chain from a boat's chain locker
D.clean chain prior to an x-ray inspection

单项选择题A carling is used aboard ship（）.

A.as a connecting strap between the butted ends of plating
B.to stiffen areas under points of great stress between beams
C.to prevent the anchor from fouling when the brake is released
D.to provide an extra heavy fitting in a heavy lift cargo rig

单项选择题A boom vang（）.

A.holds the boom down and flattens the main sail
B.draws the head of the sail to windward
C.tautens the standing rigging
D.douses the gaff topsail

单项选择题A bluff bar is a bar（）.

A.extending out from a bluff alongside the river
B.that tends to give a false indication of its position
C.that has a sharp drop off into deep water
D.that is perpendicular to the current