1. (2019高一上·嘉善月考) 编写一个VB程序，功能如下：随机产生100个0到99之间的整数，在列表框list1中显示，单击“统计”按钮Command1，统计落入各范围的整数个数，在列表框List2中按从高到低的顺序显示各范围的整数个数。程序运行界面如图所示。

实现上述功能的VB程序如下，但加框处代码有错，请改正。

Const n = 100

Dim a(1 To n)As Integer

Private Sub Form_Load( )

    ‘随机产生100个0到99之间的整数存数组a中，并在列表框list1中显示。

End Sub

Private Sub Command1_Click( )

    Dim i As Integer, j As Integer, t As Integer

    Dim b(0 To 9)As Integer, c(0 To 9)As Integer

    For i = 1 To n

           ①

    Next i

    For i = 0 To 9

        b(i) = i

    Next i

    i = 0

    Do While i <= 8

        For j = i + 1 To 9

            If  Then   ②

                t = b(i): b(i) = b(j): b(j) = t

                t = c(i): c(i) = c(j): c(j) = t

            End If

        Next j

        i = i + 1

    Loop

    List2.AddItem “范围元素个数”

    For i = 0 To 9

        List2.AddItem Str(b(i) * 10) + "~" + Str(b(i) * 10 + 9) + ": " + Str(c(i)) + "个"

    Next i

End Sub