单项选择题
A “check” line is（）.
A.a safety line attached to a man working over the side B.used to measure water depth C.used to slow the headway of a barge D.used to measure the overhead height of a bridge
单项选择题 A “bowline” is used to（）.
单项选择题 “safe speed” is defined as that speed where（）.
单项选择题 Deep-sea liners are（）.
