正确答案: C

C、ADSL2+

题目：以下xDSL技术中，关注于提高下行带宽的技术是（）

查看原题 查看所有试题

学习资料的答案和解析：

[单选题]The de facto standard Application Program Interface (API) for TCP/IP applications is the “sockets” interface. Although this API was developed for （71） in the early 1960s it has also been implemented on a wide variety of no-Unix systems. TCP/IP （72） Written using the sockets API have in the past enjoyed a high degree of portability and we would like the same （73） with IPv6 applications. But changes are required to the sockets API to support IPv6 and this memo describes these changes. These include a new socket address structure to carry IPv6 （74） ,new address conversion functions, and some new socket options. These extensions are designed to provide access to the basic IPv6 features requited by TCP and UDP applications, including multicasting, while introducing a minimums of change into the system and providing complete （75） for existing IPv4 applications.

C．Unix

[单选题]下列隧道协议中工作在网络层的是（）。

IPSec

[单选题]如果想获得细的表格边框线的效果，可以（）。

可以通过设置表格的背景色与单元格的背景色不同，并且对order，cellspacing，cellpadding的属性值进行控制得到