数组a中存放着1到20的正整数，要求对其中的元素进行分段排序，在Text2中输入每段元素的个数，在文本框Text3中显示每段降序排序后的数据，其中多余的元素不做处理。具体程序实现如图所示。

实现该功能的VB程序代码如下，请在划线处填入合适代码。
Dim a(0 To 100) As Integer
Const high = 16
Private Sub Form_Load()
Randomize
For i = 1 To high
a(i) = Int(Rnd * 20) + 1
Text1.Text = Text1.Text + Str(a(i))
Next i
End Sub
Private Sub Command1_Click()
Dim p As Integer, q As Integer, t As Integer
Dim m As Integer, n As Integer, k As Integer
m = Val(Text2.Text)
For i = 1 To ①________
c = ""
For j = 1 To m
p =②________
q = i * m
k = sort(p, q)
If a(k) <> a(p) Then
t = a(p): a(p) = a(k): a(k) = t
End If
c = ③________
Next j
Text3.Text = Text3.Text + " " + c
Next i
End Sub
Function sort(f As Integer, g As Integer) As Integer
s = f
For i = f To g
If a(i) > a(s) Then
s = i
End If
Next i
sort = s
End Function