在GSM-R系统网络拓扑中，下列哪种设备不是直接与BSC相连的（）
A.BTS
B.GGSN
C.MSC
D.SGSN
参考答案：B
— I will come to attend your lecture at 10:00 tomorrow.
— I’m sorry, by then my lecture will have ended and I _____ in my office.
A．am working
B．will work
C．will be working
D．will have worked
（）不是《孙子兵法》《记篇》中的“三战”理论。
A、慎战
B、重战
C、好战
D、备战
