在使用万用表之前要进行（）调零。
A、电子
B、机械
C、电压
D、电阻
参考答案：B
--- Why do you suggest we buy a new machine?
--- Because the old one has been damaged ___________.
A．beyond reach
B．beyond repair
C．beyond control
D．beyond description
男，46岁，外伤后左下颈搏动性肿块，CT如图所示，最可能的诊断为（）
A.左颈部血管瘤
B.左颈动脉体瘤
C.左颈静脉球瘤
D.左颈总动脉假性动脉瘤
E.左颈部动、静脉畸形
--- Because the old one has been damaged ___________.