—What's up? You didn't pick up the phone just now.

—I'm sorry that I ________    dancing with music on, but it's done now.

A．practised

B．was practising

C．am practising

D．have practiced

牙髓电活力试验患牙读数比对照牙牙明显不同，可判断患牙（）。

A.有无隐裂

B.牙髓是否坏死

C.有无咬合创伤

D.是否为急性牙髓炎

E.有无牙髓充血