原文:A man walked into a doctor's examining room."Put out your tongue,"the doctor said.The man put out his tongue and the doctor looked at it quickly."O.K.You can put your tongue back now,"the doctor said."It's clear what's wrong with you.You need more exercise.""But,doctor,"the man said,"I don't think...""Don't tell me what you think,"the doctor said."I am the doctor,not you,I know what to hear any excuses,"the patient said."I...""Doctor,you don't understand,"the patient said."I...""I don't want to hear any excuses,"the doctor said."You must find time for exercise.If you don't you will get fat and have health problems when you are older。”"but I walk every day,"the patient said“Oh,yes,and I know what kind of walking that is.You walk a few feet to the train station from your house,and a few feet for your lunch and back.That' not real walking.I'm talking about a walk in the park for twenty minutes every day.""Will you listen to me,doctor!"the patient shouted,getting angry with this doctor who thought he knew everything."I'm a mailman,"the patient went on,"and I walk for seven hours every day!"