单项选择题
When a mobile of B class is on the state of standby，what MM information is registered in SGSN？（）
A.LAI B.CI C.RAI D.None
单项选择题 What can MS do when it is standby state？（）
单项选择题 What could a MS do when its state changes from idle to ready？（）
单项选择题 When does a MS get IP address？（）
