拥有计算机并以拨号方式接入网络的用户需要使用 ( )
A．CD–ROM
B．鼠标
C．电话机
D．Modem
参考答案：D
__________he was tired, __________he didn't stop to have a rest.[ ]
A. Though; but
B. Though; /
C. But; though
D. /; /
支持单模光纤的千兆以太网物理层标准是( )。
A．1000BASE-LX
B．1000BASE-SX
C．1000BASE-CX
D．1000BASE-T
