单项选择题
One of the signals，other than a distress signal，that can be used by a rescue boat to attract attention is a/an（）.
A.red star shell B.searchlight C.burning barrel D.orange smoke signal
单项选择题 On offshore drilling units，each EPIRB or SART must be tested once every（）.
单项选择题 How can vessel personnel detect the operation of a SART in its vicinity?（）
单项选择题 How can the SART’s audible tone monitor be used?（）
