单选题

76．{{U}} (1) {{/U}}is a channel's capacity which directly reflects the data transfer rate of the channe1.
{{U}} (2) {{/U}}functions in a NetWare network which is used to define addressing schemes.
{{U}} (3) {{/U}}is a network layer device that supports multiple LAN interfaces and segments LANs into smaller collision and broadcast domains.
{{U}}(4) {{/U}}is the popular LAN developed under the direction of the IEEE802.3.
{{U}} (5) {{/U}}is a device which enables digital microcomputers to communicate across analog telephone lines.

【正确答案】 B

【答案解析】
[解析] 译文的含义是：((1))指的是能直接反映传输系统的容量，选项B正确。((2))定义NetWare网络上所使用的寻址方案(addressing schemes)，选项C正确。((3))是一种连接多种网络接口和网段，缩小广播域(broadcast domains)和冲突域 (collision domains)的网络设备，选项D正确。
((4))是应用最为广泛的局域网，符合IEEE 802.3系列标准规范，选项C正确。((5))，调制解调器(modem)能使数字计算机通过模拟电话线进行通信，选项B正确。