单项选择题
A.If B.Whenever C.Because D.Where
Before（）,a station shall take precautions to ensure tha...
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
The emergency communication set’s transmitter should no...
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
Which expression has the different meaning from entry i...
单项选择题Which expression has the different meaning from entry into force ? “entry into force” means is（）.
A.coming into effect B.moving to full effect C.being based on force D.coming into force
