[填空题] 在窗体上画一个命令按钮,然后编写如下程序: Function fun(ByVal num As Long)As LongDim k As Longk=1num=Abs(num)Do While num k=k*(num Mod 10) num=num10Loopfun=k End Function Private Sub Command1_Click()Dim n As LongDim r As Longn=InputBox("请输入一个数")n=CLng(n)r=f