" Never ______ time come again," his teacher said to him. [ ]

A. lose

B. losing

C. lost

D. will lost

阵发性室上性心动过速最多发生于（）。

A.冠心病患者

B.正常心脏者

C.高血压性心脏病患者

D.扩张型心肌病患者

E.心脏瓣膜病患者