Private Sub Command1Click()

  Dim a(-1 To 8) As Integer

  Dim i As Integer

  For i = -1 To 8

    a(i) = i * i

  Next i

  List1.AddItem Str (a(i))

End Sub

运行程序，单击命令按钮Command1后，出现的错误提示为

For i = 5 To 4 Step -1

        k = i

        For j = 6 - i To 1 Step -1

           If a(j) < a(k) Then k = j

        Next j

        If i <> k Then

           t = a(i): a(i) = a(k): a(k) = t

        End If

    Next i

数组元素a(1)到a(5)的值依次为“41，66，70，83，31”，经过该程序段“加工”后，数组元素a(1)到a(5)的值依次为（  ）

Private Sub Command1_Click()

Dim s As String, a As String, t As String

s = Text1.Text: t = ""

For i = 1 To Len(s)

    a = Mid(s, i, 1)

    If a >= "0" And a <= "9" Then

        t = t + a

    ElseIf a = "!" Then

        t = ""

    ElseIf t <> "" Then

        List1.AddItem t

    End If

Next i

End Sub

执行程序时，在文本框 Text1 中输入“12+34=46!789ok”（不包括双引号），单击按钮Command1后，在列表框List1中显示的结果是（  ）

s=“Hello world”

s1=“”

n=Len(s)

For i=1 To n\2

If Mid(s， i， 1) > Mid(s， n-i+1， 1) Then

s1=s1 + Mid(s， i， 1)

Else

s1=Mid(s， n-i+1， 1)+s1

End If

Next i

Text1.Text=s1

执行该程序段后，在文本框Text1中显示的是（  ）

        PRIVATE SUB FORM_CLICK

        DIM A（4，4） AS INTEGER

        FOR I = 1 TO 4

           FOR J= 1 TO 4

              IF {#blank#}1{#/blank#}

                A（I，J）=1

              {#blank#}2{#/blank#}

               A（I，J）=0

              END IF

              PRINT A（I，j）;

              {#blank#}3{#/blank#}

            PRINT

              {#blank#}4{#/blank#}

        END SUB