Ships are always（）on water and they are easy to rust.

单项选择题She arrived at the anchorage last night and anchored（）berth.

A.waiting
B.awaiting
C.awaiting for
D.waited

单项选择题Shall we（）wait at the roadstead till there is a free berth for us?

A.must
B.ought to
C.have to
D.never

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