单项选择题
The lifesaving signal indicating You are seen - assistance will be given as soon as possible is the（）.
A.vertical motion of white flags B.vertical motion of a white light or flare C.firing of a green star signal D.None of the above
单项选择题 The holding power of an anchor is the（）.
单项选择题 The hoist line primarily used for lifting personnel on ship cranes is called the（）.
单项选择题 The hinge fitting used to attach the boom to the mast is the（）.
