洋地黄的药理作用是()
A.正性肌力正性心率作用
B.正性肌力负性心率作用
C.负性肌力负性心率作用
D.负性肌力正性心率作用
E.电生理作用
参考答案:B, E
He went there and has stayed there . [ ]
A. three days ago; for three days
B. for three days; three days ago
C. three days before; three days
D. before three days; three days before
程序运行后,在窗体上单击鼠标,此时窗体不会接收到的事件是______。
A.MouseDown
B.MouseUp
C.Load
D.Click