根据文意及首字母提示补全短文。

    A man walked i____ a doctor's examining room. "Put out your tongue," the doctor said.   

  “OK. There is nothing s____,” 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 you need. I see hundreds of people like you. N____ of them get any exercise. They sit in the office all day and in f____ of the television in the evening. What you need is to walk quickly at l____ twenty minutes a day.”

    “Doctor, you don't understand;" the man said “I.”

    “There is no e ____,” the doctor said.  "You must spare some time for exercise. If you don’t, you will get fat and have health problems when you are old.”

    “But I walk every day," the man said.

    “Oh, yes, and I know what kind of walking that is. You walk a few metres to the office from your house, and a few more metres to a r____ for lunch and back.”

    “Please listen to me, doctor!" the man s____ at the doctor angrily.

    “I'm a mailman.”the man w____ on, “I walk for seven hours every day.”

     For a moment the doctor was silent, then he said quietly, "Put your tongue out a____, will you?"