How to i can refresh value in combobox when added , deleted data in C# - winform?

i creat void LoadData and call it whenever creat, update, view, del

     void LoadData() {
        OleDbConnection conn = new OleDbConnection();
        conn.ConnectionString = @"Provider=Microsoft.Jet.Oledb.4.0;Data Source = D:\Project\DataKTHT.mdb";
        conn.Open();
        OleDbDataAdapter ad = new OleDbDataAdapter("select * from table", conn);
        DataTable tb = new DataTable();
        ad.Fill(tb);
        dataGridView_MonHoc.DataSource = tb;
        cboMaMon.DataSource = tb;
        cboMaMon.DisplayMember = "TenMon";
        cboMaMon.ValueMember = "MaMon";
     }