SDH管理网络从下至上可以分为哪五层？
参考答案：
从下至上为网元层、网元管理层、网络管理层、业务管理层、商务管理层。
We were caught in the heavy traffic jam. Otherwise, we _____ on time.
A．would have arrived
B．arrived
C．must have arrived
D．should arrive
根据汉语意思,完成下列句子。
1.你最喜欢的影星是谁?
Who is your favorite _______ _________ ?
2.我们从周一到周五上学.
We go to school from _______ to _________ .
3.你乐意和我一起去看望大明吗?
Would you like _______ _______ Daming ?
4.电影什么时候上映?
_______ is the film _______ ?
5.我通常晚上在家做家庭作业.
I often ______ ________ _______ in the evening at home.
