Summer vacation was over and young Jack returned to school.
Only two days later his teacher phoned his mother to tell her that Jack was misbehaving.
"Wait a minute," mother said. "I had Jack with me for three months and I never called you once when he misbehaved."
A student in chemistry class was instructed to create a new substance by mixing some special ingredient with water.But the student chose the wrong ingredient and the teacher realized mixing it with water would create an explosion.
He stopped the student and asked him to first stir the water in the bucket for five minutes before adding the ingredient. The student wanted to know what that would accomplish.
The teacher answered, "It will give me time to get away."