下列各种情况中易引起室性心动过速的是

A．高钾血症

B．Q-T间期大于0.44s

C．P-R间期大于0.20s

D．预激综合征

E．完全性右束支传导阻滞

(70) is not a peripheral component or device. The basic input device on a small computer is a (71) .

A．display screen

B．printer

C．keyboard

D．card reader