A sailing vessel shall not impede the safe passage of a（）.

单项选择题A sailing vessel is overtaking a power-driven vessel in a narrow channel，so as to pass on the power-driven vessel’s port side. The overtaken vessel will have to move to facilitate passage. The sailing vessel is the（）.

A.stand-on vessel and would sound two short blasts
B.give-way vessel and would sound no whistle signal
C.stand-on vessel and would sound no whistle signal
D.give-way vessel and would sound two prolonged blasts followed by two short blasts

单项选择题A power-driven vessel pushing aheador towing alongside displays navigation lights and（）.

A.two all-round red lights in a vertical line
B.two yellow towing lights in a vertical line
C.two white masthead lights in a vertical line
D.two lights on the stern，one yellow and one white

单项选择题A power-driven vessel leaving a quay or wharf must sound what signal? （）

A.Three short blasts
B.A long blast
C.A prolonged blast
D.No signal is required

单项选择题A light used to signal passing intentions must be an（）.

A.alternating red and yellow light
B.alternating white and yellow light
C.all-round white or yellow light
D.all-round white light only

单项选择题A fishing vessel is approaching a vessel not under command. Which statement is TRUE? （）

A.The fishing vessel must keep clear of the vessel not under command
B.If the vessel not under command is a power-driven vessel，she must keep clear of the fishing vessel
C.They must exchange whistle signals
D.Both vessels are required to take action to stay clear of each other