The football player had________gift for football when he was a child.Now he is________second to none in the football field.[ ]

A. the; the  

B. the; a

C. a; the  

D. a; /

P-R间期固定，QRS波有脱漏的心电图表现是

A．Ⅱ度房室传导阻滞
B．Ⅱ度Ⅱ型房室传导阻滞
C．Ⅱ度Ⅱ型房室传导阻滞
D．Ⅲ度房室传导阻滞
E．窦房传导阻滞