第3个回答 2006-06-17
RAIN CATS AND DOGS. Rain very heavily.
When we set out there was some slight drizzle, but within twenty minutes it was raining cats and dogs.
The oridin of the expression is uncertain. Brewer's Dictionary of Phrase and Fable (ninth edition,1965) traces it back to ancient. Norse weather lore, but the explanation does not seem very convincing.