单项选择题
A vessel or object being towed astern shall display a(n)（）.
A.forward masthead light B.after masthead light C.stern light D.All of the above
单项选择题 A vessel not under command shall display（）.
单项选择题 A vessel not under command making way at night would show（）.
单项选择题 A vessel may use any sound or light signals to attract the attention of another vessel as long as（）.
