Alton, Hampshire, UK
Paul Hakimata/agefotostock/Alamy
Grinning or baring the teeth is usually a sign of aggression in animals, so at what point did it become advantageous for humans to use this to signal friendship or mirth?
Veronica Haines,
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Llanelli, Carmarthenshire, UK
a metal water barrel stands in the garden; Shutterstock ID 1980910310; purchase_order: -; job: -; client: -; other: - Shutterstock/moskvich1977
How does water become “stale”?
Bob Yelland
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