林克试图联系990航班选择呼叫系统，也没有反应。
ARINC attempted to contact Flight 990 on SELCAL, also with no response.
着重阐述了利用数字选择性呼叫技术的船舶跟踪系统的组成结构及其工作原理、技术指标；
Next, the structure, the working principles and the performance of the DSC Ship Tracking System which has been developed by the author is mainly described.
如应用程序能取回错过了来自系统的呼叫，使用者也有选择项回电。
As the application can retrieve missed calls from the system, the user also has the option to call back.
为了使电力系统通信设备的呼叫装置更加使用方便工作可靠，我们研制了以按键电话机发出双音频呼叫信号进行选择接收的音频选号装置。
In order to improve the ringing method of telephone used in power systems, a type of selective calling device using audio frequency has been developed.
系统内的任一话站均能与控制室或其他话站呼叫通话，每个话站均有选择任一通话通道的权利，系统内每个话站有六个通道，通道间没有干扰或串音。
Every station of the system can call to controlled room and other telephone station and can select every channel. There are six channel in every station and no interfere or noisy within the channel.
系统内的任一话站均能与控制室或其他话站呼叫通话，每个话站均有选择任一通话通道的权利，系统内每个话站有六个通道，通道间没有干扰或串音。
Every station of the system can call to controlled room and other telephone station and can select every channel. There are six channel in every station and no interfere or noisy within the channel.
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