For i = 1 To 10
 If d(i) >= 0 Then
   t=t+1
    List1.AddItem Str(d(i))
  Else
    t=t-1
    List2.AddItem Str(d(i))
Next
则该程序段出错的原因是缺少了（  ）

   s = ""

   For i = 1 To 5

      a(i) = 0

   Next i

   For i = 2 To 5

      For j = i To 5

         If j Mod i = 0 Then a(j) = 1 - a(j)

      Next j

   Next i

   For i = 1 To 5

      If a(i) = 1 Then s = s + Str(i)

   Next i

   Text1.Text = s

运行该程序段后，Text1中显示的内容为（  ）

为实现上述功能请在划线处填上合适代码

Private Sub confirm_Click()

Dim i As Integer, j As Integer

Dim n As Integer, m As Integer Dim k As Integer, s As String Const length=6

n=Val(Text1.Text)i=1

List1.Clear

s=""

For j=1Tolength

k=Int(Rnd()*3)+1

If k=1Then

    m=Int(Rnd()*26)+1

    s=s+Chr(Asc("a")+m-1)

ElseIf k=2Then

    m=Int(Rnd()*26)+1

    s=s+Chr(Asc("A")+m-1)

Else

    m=⑴{#blank#}1{#/blank#}

    s=s+Chr(Asc("0")+m-1)

    EndIf

    Next j

    List1.AddItemStr(i)+""+s

    ⑵{#blank#}2{#/blank#}

Loop

End Sub

For i=1 To 6

    x=Int(Rnd*10)+1

    If i Mod 2 = 1 Then

        a(i)=2*x+1

    Elself x Mod 2 = 0 Then

        a(i)=x/2

    Else

        a(i)=x-1

    End If

Next i

执行该程序段后，a(1)～a(6)各元素可能的值是（  ）

Dim c As Integer,a(0 To 5) As Integer

For i = 1 To 5

  a(i) = i

Next i

c = 0

For i = 1 To 5

  x = Int(Rnd * 5 + 1)

  If a(x Mod 5) = i + 2 Then c = c + 1

  If c = x Then Exit For

  i = i - 1

Next i

运行该程序后，变量c的值不可能是（  ）