单项选择题
A.UnloadB.DeactivateC.FormClosedD.Closing
A.Form M=new Form();showDialog(M);B.Form M=new Form();Show(M);C.Form M=new Form();M.ShowDialog();D.Form M=new Form();M.Show();
A.ExecuteReader()B.ExecuteInsert()C.ExecuteQuery()D.ExecuteNonQuery()