—Can I see you at 3:00 p.m. next Monday?

—I’m afraid not.I        to New York long before then.

A．have flown

B．will fly

C．am flying

D．will have flown

心电图上表示冲动从心房传导到心室的时间是（）

A.P波

B.P-R间期

C.QRS波

D.T波

E.U波