A.in dense fogB.in boisterous weatherC.in the open seaD……

单项选择题Radar beacons are transmitters designed to produce a（）on the screens of ship’s radar sets.

A.incorrect image
B.distinctive image
C.pictorial image
D.pictographic image

单项选择题Proper use shall be made（）radar equipment.

A.with
B.to
C.for
D.of

单项选择题No assumptions（）on the basis of scanty information，especially scanty radar information.

A.should not be made
B.are not to be taken
C.should be taken
D.shall be made

单项选择题My radar is not working.I require shore based radar assistance.Is shore based radar assistance（）?

A.used
B.available
C.in use
D.can be used

单项选择题It may be found that，in certain circumstances，radar beacon emissions can cause（）with the normal radar display，particularly at close range.

A.unwanted interference
B.unexpected figures
C.abnormal data
D.unwanted information