It is surfing on the Internet late into the night that         my getting up late.

   [      ]

A. sticks to    

B. leads to

C. results from  

D. devotes to

患者，65岁，近来心悸，心电图可见提前出现的正常QRS波群，其前P波形态与窦性P波略不相同，代偿不完全，诊断为

A．房性期前收缩
B．结性期前收缩
C．室性期前收缩
D．Ⅱ度工型房室传导阻滞
E．窦性心律不齐