acoustic impedance

1、A vessel not to impede the passage of

A vessel not to impede the passage of another vessel is not relieved （） taking collision-avoiding action.AonBofCinDfor

2、acoustic stapedius reflex

acoustic stapedius reflex

3、A vessel engaged in（）shall not impede

A vessel engaged in（）shall not impede the passage of any other vessel navigating within anarrow channel or fairway.Amine clearance operationBtowing operationCdredging or surveying or underwater operationDfishing

4、阻抗复合消声器impedance muffler

阻抗复合消声器impedance muffler

5、A sailing vessel shall not impede the

A sailing vessel shall not impede the safe passage of a（）.Apower-driven vessel following a traffic laneBpilot vessel enroute to a pilot stationClaw enforcement vesselDAll of the above