汽车自O点出发从静止开始在平直公路上做匀加速直线运动，途中在6s钟内分别经过P、Q两根电杆，已知P、Q电杆相距60m，车经过电杆Q时的速率是15m/s，则[ ]

A．车经过P杆时的速率是5m/s  

B．车的加速度是1.5m/s²

C．P、O间距离是8.5m          

D．车从出发到Q所用的时间是10s

下列程序的功能是，当一个TextBox控件被拖过一个PictureBox控件时，指针从默认的箭头变为特定的图标，当Text-Box控件被拖到其他地方时，指针恢复到默认的状态。请完成下列程序。
Private Sub Picture1_DragOver(Source As Control, X As Single, Y As Single, State As Integer)
Select Case State
Case vbEnter
Source.Draglcon=LoadPicture("JCONS\ARROWS\POINT03.ICO")
Case______
Source.Draglcon=LoadPicture()
End Select
End Sub
Private Sub Picture1_DragDrop(Source As Control, X As Single, Y As Single)
Source.Draglcon=______
End Sub