小灵通可以提供的业务功能有（）
A、来电显示、呼叫转移等固定电话所具有的一切功能
B、短信
C、无线上网
D、虚拟网功能
参考答案：A, B, C, D
治疗三叉神经痛应首选（）
A.去痛片
B.卡马西平
C.阿司匹林
D.地西泮
E.吗啡
We have been excavating layers of ash almost six metres thick, which suggests that they________the fire burning all winter.
A．should keep
B．might have kept
C．should have kept
D．might keep
