For each blank, choose the best answer from the four choices and write down on the answer sheet.

（）is a channel’s capacity which directly reflects the data transfer rate of the channel.

（）functions in a NetWare network which is used to define addressing schemes.

（）is a network layer device that supports multiple LAN interfaces and segments LANs into smaller collision and broadcast domains.

（）is the popular LAN developed under the direction of the IEEE802.3.

（）is a device which enables digital microcomputers to communicate across analog telephone lines.

（）is the popular LAN developed under the direction of the IEEE802.3.

A．Token Ring

B．Token Bus

C．Ethernet

D．FDDI

在数据分析中，对各观察值同乘以一个不等于0的常数后不变的是

A．均数
B．变异系数
C．几何均数
D．标准差
E．中位数