图图基于排序算法设计了一个数字矩阵排序的 VB 程序，功能如下：在文本框 Text1 中输入矩阵的大小 n，单击“生成”按钮 Command1，在左侧列表框 List1 中显示行数和列 数均为 n 的随机整数矩阵。单击“排序”按钮 Command2，奇数行从左到右升序排序， 偶数行从左到右降序排序，结果显示在列表框 List2 中，输出时保持矩阵大小不变。运 行结果如图所示。

请回答下列问题：
（1）实现上述功能的 VB 程序如下，请在划线处填入合适的代码。
Dim a(1 To 100) As Integer
Dim n As Integer
Private Sub Command1_Click()
Dim i As Integer, j As Integer
Dim s As String, k As Integer
n = Val(Text1．Text)
For i = 1 To n
       ①_____
       For j = 1 To n
             k = (i - 1) * n + j
             a(k) = Int(Rnd() * 45 + 5) * 2
             s = s + “ ” + Str(a(k))
       Next j
       List1．AddItem s
Next i
End Sub
Private Sub Command2_Click()
Dim i As Integer, L As Integer, R As Integer
Dim f As Integer
For i = 1 To n
If i Mod 2 = 1 Then
       f = 1
Else
       f = -1
       ②____
       R = i * n
       List2．AddItem sort(L, R, f)
Next i
End Sub
Function sort(left As Integer, right As Integer, order As Integer) As String
Dim i As Integer, j As Integer, k As Integer
Dim s As String, t As Integer s = “”
For i = left To right - 1 k = i
       For j = i + 1 To right
             If③______Then
                    k = j
       Next j
       If k <> i Then
             t = a(k): a(k) = a(i): a(i) = t
       End If
       s = s + “ ” + Str(a(i))
Next i

sort = s
End Function
（2）若删除上述 VB 程序中加框处代码，_______（选填：会/不会）影响程序运行结果。