单项选择题
A.Sound one blast of the whistle
B.Alter course to starboard
C.Construct a radar plot
D.Sound the danger signal
单项选择题 A vessel has sustained damage in a collision with another vessel. It is necessary to have a Seaworthy Certificate before the vessel sails. Who will issue this certificate?（）
单项选择题 A vessel engaged in fishing underway sounds the same fog signal as a（）.
单项选择题 A vessel constrained by her draught shall，when risk of collision with another vessel in a crossing or head-on situation exists，（）.