The Dogs Duties_英语动物笑话

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."