急性心肌梗死发生心室颤动的先兆是
A．房性早搏
B．室性早搏频发、成对、多源出现
C．室上性阵发性心动过速
D．心房纤颤
E．房室传导阻滞Ⅱ度
参考答案：B
下列何种情况不宜妊娠（）
A.心功能Ⅲ级、Ⅳ级
B.活动性风湿病或伴有细菌性心内膜炎
C.肺动脉高压
D.慢性房颤
E.先天性心脏病紫绀型
Co-operation or teamwork, the importance of which is often ________, plays an important part in football matches.
A．stressed
B．thought of
C．paid much attention
D．talked
