A notoriously absent-minded professor was one day observed walking along the street with one foot continually in the gutter, the other on the pavement. http://www.xue90.cn来自《幽默学英语》网
A pupil meeting him said:
"Good evening, professor. How are you?"
"Well," answered the professor, "I thought I was all right when I left home, but now I don't know what's the matter with me. I've been limping for the last half-hour."