David was ill. He went to see a doctor. The doctor asked him to_______ his tongue (舌头), and then he said, “ OK. You can put your tongue back now. There’s ______ wrong with you, but I’m afraid you have a problem, you never take ______.”

“But, doctor,” David said, “I don’t think so.”

“Don’t ______me what you think,” the doctor said, “I see a lot of people _______you. None of them get any exercise. They sit in offices all day and in front of the TV in the evening. You must walk quickly for at least 30 minutes a day.”

“Doctor, you don’t understand, ”David said, “ I take enough exercise every day. ”

“I don’t want to ______ any excuses,” the doctor said, “You must find time______   exercise. If you don’t, you will get ______ and have health problems.”

“But I walk every day.” David said.

“Oh, yes, and I know what kind of walking that is. You walk________meters to the bus stop from your house, from the bus stop to your office, and from your office to your dining-room for lunch and back. That’s not a real walk. I’m talking about a walk by the lake or in the park for 30 minutes every day. ”

“Would you please ______ me, doctor?” David said, “I’m a postman. I walk for nearly seven hours every day.”

For a moment the doctor was silent, then he said,“Can I see your tongue again?”