Сравнить два ComboBox и вывести элементы, которые есть в обоих

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        For i = 0 To ComboBox1.Items.Count - 1
            For j = 0 To ComboBox2.Items.Count - 1
                If ComboBox1.Items(i).ToString = ComboBox2.Items(j).ToString Then
                    Label8.Text += ComboBox1.Items(i).ToString & vbCrLf
                End If
            Next
        Next
End Sub

For Each line As String In File.ReadLines("file.txt", Encoding.Default)
            ComboBox1.Items.Add(line)
Next

Label1.Text = String.Join(vbCrLf, ((From el In ComboBox1.Items).ToArray.Intersect(From el In ComboBox2.Items).ToArray).ToArray)

Private Sub Form4_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    ComboBox1.Items.AddRange({"Иванов", "Степанов", "Петров", "Цветков", "Ливанов", "Пучков"})
    ComboBox1.SelectedIndex = 0
    ComboBox2.Items.AddRange({"Пушкин", "Лермонтов", "Степанов", "Федоров", "Цветков", "Хрущев", "Ливанов", "Пучков"})
    ComboBox2.SelectedIndex = 0
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    ListBox1.Items.Clear() 'в ListBox1 будем собирать дубли
    For Each it1 As String In ComboBox1.Items
        If ComboBox2.Items.Contains(it1) Then
            ListBox1.Items.Add(it1)
        End If
    Next
End Sub