A local-area network (LAN) is a communications network that (125) a variety of devices and provides a (126) for information exchange among those devices. The scope of the LAN is small typically a single building or a cluster (丛) of buildings. The LAN is usually owned by the same organization that owns the (127) devices. The internal data rate of LAN is at least several Mb/s.
The basic of LAN communication is broadcasting. At each station, there is a transmitter/receiver that communicates over a (128) shared, By other stations. A transmission from any one station is (129) to and received by all other stations.
（129）是（）
A.broadcast
B.cable
C.control
D.interconnects
E.internet
F.meander
G.means
H.medium
I.modem
J.output switch relay
参考答案：A
解析：
局域网是将许多设备互连在一起并提供一种在这些设备间交换信息的方法的通信网络。局域网范围小，通常只在一个建筑物或一群建筑物范围内。一个局域网通常为拥有互联设备的同一个组织所拥有。局域网的内部传输率至少为数Mb/s。局域网的基本通信方式为广播方式。每个站都有一个转发/接收器，通过一个与其他站共享的媒介来通信。从任何一个站发送的消息都被广播到所有的站并被这些站接收。