private void rad_OnlyOneAnswer_CheckedChanged_1(object sender, EventArgs e)
{
if(!pnl_LoadQuestion.Controls.Contains(Question_OnlyOneSelect_1.instance))
{
pnl_LoadQuestion.Controls.Add(Question_OnlyOneSelect_1.instance);
//Question_OnlyOneSelect_1.instance.Dock= DockStyle.Fill;
Question_OnlyOneSelect_1.instance.BringToFront();
}else
Question_OnlyOneSelect_1.instance.BringToFront();
}