In a certain group of people,

of the people are men, and

of the men have brown eyes. If

of the people have brown eyes, then what fraction of the group are women who do not have brown eyes

患者，女，70岁，阵发性房颤5年，应用胺碘酮长期口服控制良好。

下列各种情况中，需用抗心律失常药物治疗的是

A．有症状的室性心动过速

B．房颤心室率78/min

C．预激伴发快速房颤

D．无意中发现的频发室性期前收缩

E．一度房室传导阻滞