A.mustB.ought toC.have toD.neverShall we（）wait at the r……

单项选择题Routine radio communications should be no more than（）.

A.one minute
B.three minutes
C.five minutes
D.eight minutes

单项选择题PORT A BIT SLUGGISH means that port rudder（）.

A.answers very well
B.rudder answers all right
C.answers slow
D.answers fast

单项选择题Free communication effect is in direct proportion to（）.

A.length and width of space
B.length of space only
C.width of space only
D.neither length nor width

单项选择题Electrical wiring on all T-Boats must be（）.

A.concealed to prevent mechanical damage
B.concealed so the boat can be maintained more easily
C.protected from the weather
D.in an accessible place behind the ceiling

单项选择题DO NOT，REPEAT，NOT OVER-TAKE means that you should（）.

A.overtake
B.not overtake
C.overtake or not
D.decide if you should overtake