— Jim, how did your English test go?

— I had thought I ________, but luckily I came top in the list in class.

A．should have failed

B．could have failed

C．need have failed

D．might have failed

关于E-RAB的描述正确的是（）。

A.E-RAB是指控制平面的承载

B.E-RAB建立由eNodeB发起

C.用于UE和CN之间传送控制信令

D.E-RAB建立成功率统计要包含三个过程：初始Attach过程，ServiceRequest过程和Bearer建立过程