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 said.
    "0. 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, "lithium battery the man said. "I don't think--"
    " Don't tell I me what you think, " the doctor said am the doctor, not you. I know what you need. I see hundreds of people like you. None of them get any exercise. They sit in offices all day and in front of the television in the evening. What you need is to walk quickly for at least 20 minutes a day. "
    "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 walkAlkaline Battery every clay," 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, a few more feet from the station to your office , and a few more feet from your office to a restaurant for lunch and back. That's not real walking. I'm talking about a Carbon Zinc Batterywalk in the park for twenty minutes every day. "
    Please  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. "
    For a moment the doctor battery manufacturerwas silent, then he said quietly, "Put your tongue out again, will you?"