If a ship is proceeding towards the magnetic equator，the uncorrected deviation due to permanent magnetism（）.

单项选择题How does an icebreaker normally free a ship which has become beset while navigating independently?（）

A.By backing down the track and cutting out ice on either bow
B.By approaching from the stern and crossing ahead at an angle of 20°to 30°to the beset ship's course
C.By overtaking the beset ship，running ahead and then backing down the track to the beset vessel
D.By approaching the vessel from astern and towing the beset vessel stern first

单项选择题Every vessel should at all times proceed at a safe speed. Safe speed is defined as that speed where（）.

A.you can stop within your visibility range
B.you can take proper and effective action to avoid collision
C.you are traveling slower than surrounding vessels
D.no wake comes from your vessel

单项选择题Every vessel shall proceed at a safe speed（）the prevailing circumstances and conditions

A.adapted to
B.used by
C.liable to
D.adaptation to

单项选择题Every vessel shall at all times proceed at a safe speed so that she can（）.

A.take proper and effective action to avoid collision
B.be stopped within a distance appropriate to the prevailing circumstances and conditions
C.neither A nor B
D.both A and B

单项选择题As you approach Shreves cut-off you see Red River LandingGage (302.4 AHP) which reads 4.2 feet. Which of thefollowing statements is TRUE? （）

A.This reading is at the same elevation as the 6.2 ft. mark on the gage at Head of Passes
B.A vessel drawing 8 ft would be able to pass over the sill at Old River Lock
C.This reading is 6.4 feet below the Low Water Reference Plane
D.A vessel drawing 7 ft. would be able to pass through the locks at Lower Old River