航海英语航海图书资料单项选择题每日一练(2019.01.11)

单项选择题
The Earth has the shape of a(n) （）.
A.sphere
B.oblate spheroid
C.spheroid of revolution
D.oblate eggoid
单项选择题
Coral atolls，or a chain of islands at right angles to the radar beam，may show as a long line rather than as individual targets due to （）.
A.the effects of beam width
B.limitations on range resolution
C.the pulse length of the radar
D.the multiple-target resolution factor
单项选择题
Attention is called to the fact that in many cases charted depths may be decreased by up to （）.
A.one nautical mile
B.two kilometers
C.5 cables only
D.one fathom
单项选择题
The description Racon beside an illustration on a chart would mean a （）.
A.radar conspicuous beacon
B.circular radiobeacon
C.radar transponder beacon
D.radar calibration beacon
单项选择题
Place names used should be those （）.
A.specified by international authorities
B.specified by national authorities
C.on standard map
D.on the chart or Sailing Directions in use