二尖瓣前叶细颤可见于：()
A．二尖瓣关闭不全
B．主动脉瓣关闭不全
C．三尖瓣关闭不全
D．二尖瓣脱垂
E．左室内径增大
参考答案：B
There were dirty marks on her trousers _______ she had wiped her hands.
A．when
B．which
C．where
D．That
人力资源开发不是人力资源管理的重要内容。
