目前在电信城域网网络中使用的组播路由协议是（）。
A、PIM、SM
B、PIM、DM
C、MSDP
D、ISIS
参考答案：A
Would you please tell me why all of you refused to do as _____ that day? [ ]
A. to be told
B. told
C. had been told
D. being told
司法机关应当积极主动地为市场经济主体服务。 ( )
