The Carburettor
"The car won't start," aid a wife to her husband. "I think there's water in the carburettor."
"How do you know?" said the husband scornfully. "You don't even know what the carburettor is."
"I'm telling you," repeated the wife, "I'm sure there's water in the carburettor."
"We'll see," mocked the husband. "Let me check it out. Where's the car?"
"In the swimming pool."