10 things we didn't know last week.

1. Quantas' Sydney to Dallas service is the world's longest commercial flight at 8,568 miles (13,790 km).

Find out more (Economist)

2. Mothers think the youngest child is shorter than they really are despite correctly estimating the height of their other children.

Find out more (New Scientist)

3. An apple a day really does keep the doctor away, especially for the over-50s.

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4. There is only one floating cat sanctuary in the world - in Amsterdam.

Find out more (Vice)

5. Penguins huddle like traffic jams, using a stop-go series of movements to keep the group warm.

Find out more (Daily Mail)

6. Tea is more popular in France than coffee is in Britain.

Find out more (Economist)

7. Cliff Richard's hit Mistletoe and Wine was

was originally written as a protest song about poverty.

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8. The fashion for tight-fitting jeans caused problems for the manufacture of dollar bills.

Find out more (Washington Post)

9. One in every 200 young American women says they became pregnant while still a virgin.

Find out more (the Times)

10. The British send more traditional greeting cards per capita than any other country in the world.

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