单项选择题
A.the first port of call
B.any port of call
C.the last port of call
D.the destination
单项选择题 Orders of the Master to the officer of the watch which s/he must comply with are（）.
单项选择题 In determining that the（）of the navigational watch is adequate to ensure that a proper look-out can continuously be maintained，the master shall take into account all relevant factors.
单项选择题 If in any doubt as to the pilot’s actions or intentions，the officer in charge of the navigational watch shall（）.