问答题 高速数据主干网的一个建设重点是解决“最后一公里”的问题，图1-1所示的四个社区采用的小区宽带接入方法分别是：社区1（1），社区2（2），社区3（3），社区4（4）。除了这几种宽带接入方法外，采用有线电视网进行宽带接入的方法是（5），利用电力网进行宽带接入的方法是（6），遵循IEEE802.16标准进行宽带接入的方法是（7）。空（1）～（7）,备选答案： A．FTTx+PON B．HFC C．FTTx+LAN D．WLAN E．WiMax F．xDSL G．PLC ( Power-Line Communication) H．GPRS

单项选择题 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.

单项选择题 PC机不能接入因特网，这时采用抓包工具捕获的以太网接口发出的信息如下图：可以看出该PC机的IP地址为（）