在卷取过程中通过（）装置对带钢边缘进行监视，操纵机座移动油缸使卷取机浮动。
A.辊形控制
B.边缘控制
C.波浪程度
D.表面精度
参考答案：B
已知数列{an}的前n项和为Sn，且Sn=2an-2，（n=1，2，3…）
（1）求数列{an}的通项公式；
（2）记Sn=1•a1+3•a2+…+（2n-1）an，求Sn．
(66) is a channel’ s capacity which directly reflects the data transfer rate of the channel. (67) functions in a NetWare network which is used to define addressing schemes. (68) is a network layer device that suports multiple LAN interfaces and segments LANs into smaller collision and broadcast domains. (69) ．is the popular LAN develped under the direction of the IEEE 802.3. (70) is a device which enables digital microcomputers to communicate across analog telephone lines.
A. The repeaterB. The modem C. The hub D. The printer
