Clear all combox controls expect those in Array

private void Form1_Load(object sender, EventArgs e)
        {
            comboBox1.Items.AddRange (new string[]{"mohamed","Ahmed","Nader"});
            comboBox2.Items.AddRange(new string[] { "mohamed", "Ahmed", "Nader" });
            comboBox3.Items.AddRange(new string[] { "mohamed", "Ahmed", "Nader" });
      
        }
        private void EmptyCombo(Control C,string[] CombNames)
        {

            foreach(Control CombType in C.Controls)
                {
                    if (CombType is ComboBox)
                    {
                        foreach (string name in CombNames)
                        {
                            if (CombType.Name == name)
                            {
                                (CombType as ComboBox).Text = "Choose Your Value";
                            }

                        }
                        if ((CombType as ComboBox).Text != "Choose Your Value")
                        {
                            (CombType as ComboBox).DataSource = null;
                            (CombType as ComboBox).Items.Clear();
                        }
                    }
                    else
                    {
                        if (CombType is GroupBox)
                        {
                            EmptyCombo(CombType, CombNames);
                        }
                    }
                }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            EmptyCombo(this, new string[] {"comboBox1","comboBox3"});
        }

    }
}

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