具有确诊意义的检查是

A．冠状动脉造影

B．24小时动态心电图

C．心肌核素显像

D．超声心动图

— What do you mean by saying every minute counts?

— I just mean that every minute must be made full use of ______ for the final examination. [ ]

A. prepare        

B. prepared      

C. preparing    

D. to prepare