If the plane is downed in the ocean, the black box sends out a signal that can travel up to three kilometers away.
如果飞机坠入大海，黑匣子会发送信号，三公里外都能追踪到该信号。
2
The municipal central meteorological observatory of Shanghai said the typhoon will not grow weakened until Sunday morning and already sent out a black warning signal Saturday.
上海市中心气象观测站说到周日早上前台风的势头不会减弱，并已在周六颁布了黑色台风警告。
3
In the firstone. black clouds of exhaust fume are emitted from a highchimney. to thes trend one. a signal tower stands instead ofthe ugly chimney. sending out invisible harmful radiation.