communication and alarm
... communication accessories 通信设备附件 communication and alarm 通信和警报 communication and electronics 通信与电子学 ...
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国家用于人民防空通信的专用频率和防空警报音响信号，任何组织或者个人不得占用、混同。
No organizations or individuals may use the same frequency or the same acoustic signals as those specially used by the State for civil air defense communications or air defense warning.
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