在计算机网络系统中，WAN指的是( )。
A．城域网
B．局域网
C．广域网
D．以太网
参考答案：C
I wrote _____ my brother last Saturday, but I haven't heard _____ him up to now. [ ]
A. from; to
B. to; of
C. to; to
D. to; from
在我国实施“督政”的意义何在？
