SDH复用映射结构中的同步传送模块由N个STM-l信呼以同步复用方式构成,它代表一个具有()速率的STM—N信号的帧。
参考答案:标准等级
— Is that ____________ mother?
— No, she is ____________ mother.[ ]
A. my, your
B. your, my
C. your, his
D. you, you
述电力机车弹簧装置的作用?