单项选择题
A.danger
B.I am in distress
C.the vessel is not under command (broken down)
D.I am operating astern propulsion
单项选择题 The signal to guide vessels in distress，which indicates，“This is the best place to land” is the（）.
单项选择题 The service life of distress signals must be not more than（）.
单项选择题 The regulations require that inspected vessels on an international voyage，other than small passenger vessels，must carry which of the following distress signals on or near the navigating bridge?（）