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1957年,当苏联的首颗卫星发射升空时,美国科学家突发奇想:卫星反射回地面的信号,能够精确定位接收者的位置!这便有了GPS全球定位系统,如今它却频频发生状况……
When the first Soviet satellite was launched into space in 1957, American scientists came up with a whim: the satellite reflected the signal back to the ground and pinpointed the location of the receiver. With the help of the GPS global positioning system, it is now a frequent occurrence ...