单项选择题
You can safely step in the bight of a line（）.
A.when it is not under strain
B.if both ends are made fast
C.in an emergency
D.at no time
点击查看答案&解析
相关考题
-
单项选择题
When a pilot is on board to pilot the vessel the Letter（）must be hoisted.
A.G
B.H
C.B
D.N
