此心电图诊断为（）
A.房性早醇
B.窦性早博
C.室上速
D.心房纤颤
E.室早二联律
参考答案：E
康明斯发电车中，冷却风机低速运行时转速为（）。
A.18.5r/min
B.5r/min
C.960r/min
D.650r/min
—________did your uncle leave his hometown?
—He ________ for nearly twenty years.
A．When; has left
B．When; has been away
C．How long; has left
D．How long; has been away
