14、A doctor once taught a class of students in a famous hospital in Edinburgh (爱丁堡). Someone _ _ _ 21 _ _ _ a sick man in, and the doctor turned to one of the students and asked him, "What's wrong with this man?"
"I don't know, sir," the student answered. "Shall I examine him to _ _ _ 22 _ _ _ what his problem is?"
"There's no need to examine him," said the doctor. "You should know without asking questions. He hurt his right knee. Didn't you _ _ _ 23 _ _ _ the way he walked? He hurt it by burning. You see his trouser leg is burnt at the knee. It is Monday morning now. Yesterday was fine, but on Saturday the roads were wet and muddy (泥泞的). The man's trousers are muddy all over. The man _ _ _ 24 _ _ _ on Saturday night."
Then the doctor turned to the man and said, "You had your wages on Saturday and went to a _ _ _ 25 _ _ _ and drank too much. You got wet and muddy on the way home. Because you drank too much, you fell on the fire and burnt your knee. Is that right?"
"Yes, sir," said the man.