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（）?
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.
