单项选择题
When will the float-free emergency position indicating radiobeacon be activated after abandoning ship? （）
A.Immediately after floating free B.After about one hour when the salt water activates the battery C.Only when keyed by the radar of another vessel D.Only when daylight activates the photovoltaic cell
单项选择题 When using the radar for navigating（）.
单项选择题 When using the ARPA in heavy rain，which action should you take? （）
单项选择题 When using an ARPA，what should you consider in order to evaluate the information displayed?（）
