18.戒煙的一個良方就是不靠外援，馬上戒。 (A) One of the good ways in quitting smoking is to do it right away with no excuses. (B) A good way to quit smoking is stopping the habit suddenly with no assistance. (C) Finding no excuses, or assistance, to quit smoking; just do it as long as you are ready. (D) Quitting smoking is looking for no help; people usually say it and do it differently.