把多个信号调制在不同的载波频率上，在同一介质上实现同时传送多路信号的技术称为__________。
参考答案：频分多路复用（或FDM）
用所给词的适当形式填空。
1. Look! The boy _____ (tie) his shoes over there.
2. My mother _____ (cook) when my father was reading a newspaper.
3. There _____ (be)a class meeting this evening.
4. My father often _____ (drive) to work.
5. Danny _____ (live) in China for three years.
iPad与计算机进行数据同步时，每个账号最多可对（）台计算机授权。
A.4
B.5
C.6
D.7
