The foreign seafarers said goodbye to us and looked forward to（）each other soon.

单项选择题In the IMO SMCP the situations（）phrases using the work “can” appear it clear whether a possibility is referred to.

A.where
B.when
C.after
D.unless

单项选择题（）it is advisable to remain on a VHF channel 8, say: “stand by on VHF channel 8”.

A.That
B./
C.When
D.What

单项选择题（）we stand away from the church bell, it takes time for the sound waves to each us.

A.If
B.Whenever
C.Because
D.Where

单项选择题Before（）,a station shall take precautions to ensure that its emission will not interfere with transmission already in progress.

A.transmit
B.to transmitting
C.transmitting
D.in transmitting

单项选择题The emergency communication set’s transmitter should not be tested except when（）by a public radio inspector.

A.inspecting
B.inspected
C.inspects
D.having inspected