The story is told of four high school boys who couldn't resist the temptation to skip morning classes. Each had been smitten with a bad case of spring fever. After lunch they showed up at school and reported to the teacher that their car had a flat tire. Much to their relief, she smiled and said, "Well, you missed a quiz this morning, so take your seats and get out a pencil and paper." Still smiling, she waited as they settled down and got ready for her questions. Then she said, "First question which tire was flat?"