Private Sub Command1_Click()

    Dim s As String, ch As String

    Dim i As Integer, k As Integer

    Dim L As Integer, R As Integer

    Dim temp As Integer, min As Integer

    s = Text1.Text

    i = 1: k = 0: temp = 0: min = 100

    Do While i <= Len(s)

        ch = Mid(s, i, 1)

        If ch >= "0" And ch <= "9" Then

            temp =________

        Else

            k = k + 1

            If  ________  Then

                L = temp

            Else

                R = temp

                If R - L + 1 < min Then min = R - L + 1

            End If

            temp = 0

        End If

        i = i + 1

    Loop

    Label2.Caption = "最短区间长度是" + Str(min)

End Sub

“觅求真知”图层第30帧到第50帧实现了“觅求真知”文字逐渐消失的动画效果，

则第50帧实例的Alpha值为________，若第50帧实例的宽和高分别为(54,20)，x和y分别为(70,390)，实现的动画效果是________（单选，填字母：A .向右下方移动并变小 / B .向左下方移动并变小 / C .向左下方移动并变大）