二度Ⅱ型窦房传导阻滞的心电图表现是（）

A.长间歇有规则的出现

B.P-P间距逐渐缩短，但无脱漏

C.长间歇后出现房性、交界性或室性逸搏

D.心室律规则

E.在一段长间歇中无P-QP，S-T，间歇常等于正常窦性P-P间距的2倍或3倍

--- Do you doubt ____ he’ll be fired by the school?    

--- No, not a bit. But I doubt ____ he will bury himself into study.

A．that; that

B．whether; /

C．if ; that

D．that; whether