by long distance
by the darkness at night
by a vessel in front
by fog or falling snow
第1题：
When visibility is reduced to about 5 miles, we say that visibility is________.
A.very good
B.good
C.poor
D.moderate
第2题：
Where will you find the requirements for the signals that must be sounded by a mobile offshore drilling unit that is being towed through an area of restricted visibility?
A.COLREGS
B.MMS Rules
C.SOLAS Convention
D.Coast Pilot
第3题：
Information, in its most restricted technical sense,is a sequence of symbols that can be interpreted as a messag
A.Information can be recorded as signs,or transmitted as__(75)__.
B.symbols
C.message
D.signals
E.wav
第4题：
第5题：
In restricted visibility, a vessel which detects by radar alone the presence of another vessel shall determine if a close quarters situation is developing or risk of collision exists. If so, she shall __________.
A.sound the danger signal
B.when taking action, make only course changes
C.avoid altering course toward a vessel abaft the beam
D.All of the above
第6题：
In restricted visibility the speed of a vessel without operational radar may be ________ enable effective avoiding action to be taken on sighting another ship．
A.too low to
B.too high to
C.too high for
D.too low for
第7题：
According to the Rules, when should lights be displayed?______.
A.During the hours of darkness
B.At all times when underway
C.From sunset to sunrise and restricted visibility
D.Sunrise to sunset
第8题：
Information,in its most restricted technical sense,is a seque of symbols that can be interpreted as a message.ingormation can be recorded as signs,or transmitted as（）
A.symbols
B.message
C.signals
D.wave
第9题：
第10题：
Which three things can be restricted by the Class of Service in a traditional PBX？ （）