Dim a(1 To 10) As Integer

 Dim s(1 To 10) As Integer

 Private Sub Form_Load()

  a(1) = 3: a(2) = 6: a(3) = 8: a(4) = 4: a(5) = 9

  a(6) = 5: a(7) = 3: a(8) = 3: a(9) = 10: a(10) = 5

 End Sub

 Private Sub Command1_Click()

 Dim i As Integer, t As Integer

 s(1) = a(1)

 For i = 2 To 10

  s(i) = s(i - 1) + a(i)

 Next i

 t = s(8) - s(4)

 Text1.Text = Str(t)

End Sub

程序运行后，文本框Text1显示的内容是（  ）

 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（  ）

For i= 1 To 3

For j= 1 To 5-i

     If a(j) >a(j+1) Then

         t=a(j)：a(j)=a(j+1)：a(j+1)=t

     End  If

     Next j

     Text 1．Text=Text 1．Text+str(a(i) )

Next i

数组元素a(1)到a(5)的值依次为“3，9，6，8，4”。该程序段执行后，文本框Text 1显示的内容是（  ）

i = n

Do While i >=2

k = i

For j =            To 1 Step -1

If a(j) > a(k) Then k = j

Next j

If i <> k Then

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

End If

Loop

则下列说法正确的是(  )