A professor invented a…

A professor invented a lie detecting chair. Whenever anybody sitting in it told a lie, the chair would open up and dump the liar on the floor. During an experiment, a brunette sat in the chair and the professor asked her to tell about herself. She began, “I think you are the best teacher I’ve ever had. ” The chair immediately dumped her on the floor. After the brunette left in a snit, a blonde sat in the chair. The professor asked him to tell something of his life. He began, “I think -” The next thing he knew, he was sitting in the floor.