网络故障分类有（）
A.业务故障
B.设备故障
C.网络故障
D.通信故障
参考答案：A, B
--- Mary knows so much about ______earth!
---Yes, although she is only ____eight- year-old girl.
A．an; a
B．the; an
C．the; a
D．an; an
KP
