分析在GSM系统需用回音消除器的原因.
参考答案:
⑴GSM数字系统处理延时较大(180ms以上).
⑵二–四线转换时泄漏.
⑶存在于L(陆地边)–M(移动边)的M侧.
— There are so many current styles, which one should I choose?
— ________.
A.It’s your opinion
B.I don’t mind
C.It’s all up to you
D.That’ s your decision
John always says that he likes apples of all the _____. [ ]
A. vegetables
B. fruits
C. drinks
D. drink