Q: If H20 is on the inside of a fire hydrant, what is on the outside?
A: K9P

A nursery school teacher was delivering a station wagon full of kids home one day when a fire truck zoomed past. Sitting in the front seat of the fire truck was a Dalmatian dog. The children fell to discussing the dog's duties. "They use him to keep crowds back," said one youngster. "No," said another, "he's just for good luck." A third child brought the argument to a close. "They use the dogs," she said firmly, "to find the fire hydrant."

How is it one careless match can start a forest fire, but it takes a whole box to start a barbecue?