After determining that the frequency or channel appears to be no longer in use
After determining that geographic distance from the distress situation will prohibit any other signal from interfering with emergency communications
Routine communications can resume after the Rescue Coordination Center transmits a message on the frequency or channel being used for emergency communications stating that such traffic has concluded
If，in the Master's opinion，communications on that frequency will interfere with emergency communications
第1题：
B
Radio and television are very popular in the world today． Millions of people watch TV．Perhaps more people listen to the radio．The TV is，of course，more useful than the radio． On TV you can see and hear what is hap-pening in the world．Now radio is still with us． And the number of listeners is becoming larger． One reason for this is the invention of the transistor(半导体) radio． A transistor radio is sometimes very small． It is very easy to carry． You can put one in your pocket and listen to it on the bus or on your bike when you go to work． It is better．for blind people． The sight(视力J) of many old peo-ple is not good enough to watch TV． Then，when people are working，they can't watch TV， but they can listen to music or news over the radio． What-s more，radio is much cheaper than TV．
( )26． Radio and television__________ in the modern world today
．
A． are both widely used
B． are both expensive
C． have been changed a lot
D． are used for learning things
第2题：
A. could stay
B. could have stayed
C. can stay
D. must have stayed
第3题：
发生火情时，客人们能用电梯吗?
A.Can guests use the stairs when a fire appears?
B.Can guests use the elevators when a fire presents?
C.Can guests use the lifts when a fire occurs?
D.Can guests use the ladders when a fire breaks up?
第4题：
What does the underlined sentence "So when it goes down, you go down with it." mean?
A. When computer doesn't work, you cannot work too.
B. When computer falls down, you fall down with it.
C. When computer is working, you can do nothing.
D. You can sell ticket without asking the computer.
39．答案为A 通过上文的描述，得知电脑死机后，人们无法正常工作。得出答案A。
第5题：
I was listening to the radio ____ washing clothes.
A. as
B. while
C. the time
D. when
第6题：
29．__________ when you are on the bus or bike．
A． Radio can be listened
B．TV can be watched
C． Radio can be listened to
D． TV can be used
第7题：
At a dinner, you can begin to eat
A、when the guests sitting beside you begin.
B、when the hostess says, "Let's begin."
C、when the main course is served.
D、when the hostess picks up her own spoon or fork..
第8题：
24． Which of the following is TRUE?
A． When he talks or sings, Jay Chou can both speak clearly．
B． When he sings, Jay Chou can-t speak clearly． When he talks, he can't, either．
C． When he talks, Jay Chou can-t speak clearly． But when he sings, he can．
D． When he sings, Jay Chou can't speak clearly． But when he talks, he can．
第9题：
A. when they receive a special token
B. when there is a carrier
C. when they detect no other devices are sending
D. when the medium is idle
E. when the server grants access
第10题：
When should the emergency position-indicating radio beacon be activated after abandoning an OSV ________．
A.Immediately
B.After one hour
C.Only when another vessel is in sight
D.Only after sunset