多年来，通信网主要采用铜线(缆)用户线向用户提供传送电话的业务，用户铜线(缆)网分布广泛且普及，为了进一步提高铜线传输速率，开发了（　）技术，以解决高速率数字信号在铜缆用户线上的传输问题。

The full title of the U.K. is the United Kingdom of （）and （）

填空题查看答案

主要包括用户交换设备、通信线路和用户终端设备三大部分，为建筑物内各类人员提供通信服务的系统称为（　）。

单选题查看答案

通信网中的用户线多数是0.5mm的铜线，且是二线制。

判断题查看答案

public and private colleges and universities and community colleges offer（）.

单选题查看答案

（）is used for calling and replying,and for transmitting acknowleding and relaying distress alerts.

单选题查看答案

The way in which people address each other depends on their age, sex, social group and personal relationship. The English system of address forms frequently used includes first name, last name, title+last name, （）, and kin term.

单选题查看答案

串联一个常开触点时采用OR命令，并联一个常开触点时采用AND指令。

判断题查看答案

Solid waste generation，and electricity and water consumption are costly and have their own set of environmental（）.

单选题查看答案

Whose duty is it to examine and verify the vessel’s classification and technical state and condition?（）.

单选题查看答案