TDMA
参考答案：
时分多址，是以传输信号存在的时间不同来区分信道的接入方式。
-Has your former classmate come back from America?
-Yes ，he________there for eight years.[ ]
A．has stayed
B．stays
C．stayed
D．had stayed
The film was made _____ the World War Ⅱ. [ ]
A. base on
B. based on
C. base in
D. based in
