Dinosaur

Dinosaur
Originally uploaded by menlo.

A student on a class trip to the natural-history museum asks the guard, "Can you tell me how old the dinosaur bones are?"

The guard tells him, "Three-million-four years and six months old."

The student says. "How do you know that so precisely?"

The guard says, "Well, the dinosaur bones were three million years old when I started working here, and that was four and a half years ago."