简述本单位语音通信交换系统的系统配置、席位配置及接口设备。
参考答案：
系统配置：主机、电源、席位终端。主机是由各种功能板构成，一台最简单的主机也要由一块席位板、一块功能板、一块监控板和两块交换板组成。电源：由两路相互隔离，并可独立运行的电源构成。
席位终端：是由控制主机、可触摸显示屏、音频输出设备、音频输入设备构成。
接口：系统连接包括主机与终端席位之间、席位本身、主机与外部设备（甚高频电台、程控电话和直通电话）之间的连接。所有端口均对应于本设备后面的ＤＢ９功能接口。
| It sounds like a science fiction, but researchers say it’s a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too. The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte—literally, "fish killer." It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding. Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish’s nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them. Whether humans are affected by the dinoflagellate’s toxin remains to be seen. Researchers think it’s unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation. To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack. |
Which of the following does the writer explain
A．Neurotoxins.
B．Microscopic organisms.
C．Predators.
D．Fish walks.