10 things we didn't know last week
16:59 UK time, Friday, 23 March 2012
1. It rains liquid methane once every 1,000 years on Titan, the largest moon orbiting Saturn.
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2. Barack Obama knows sign language.
3. Holding a gun makes you more likely to think other objects are guns.
4. The Welsh language can be confused with Hebrew.
5. Female animals can have ovaries on the outside.
6. Noise stunts the growth of plants.
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7. Listening to opera helps mice recover from heart surgery.
8. A cat can fall 19 storeys and survive.
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9. Birds take "girls only" holidays.
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10. The UK is the world's third-largest purchaser of human hair.
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