单项选择题
VHF radio is one of the very important navigational instruments on board,（）messages can be sent.
A.by which B.through which C.by that D.through that
单项选择题 When（）,the provision of the bill of lading will be used as a basis for settlement.
单项选择题 When the（）is large, the ship is stiff; and when it is small, she is tender.
单项选择题 When the ship causes oil pollution to the port, she will be（）.
