91色情片

Last Word

A young child has both his thumbs on middle C. There are stickers on each key to guide him through the octaves and notes.

Why do we only use 12 notes in Western music?

Why do we only use 12 notes in Western music?

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2C166J1 Silhouette of a human with skin flora,microorganisms which naturally colonize the human skin - 3d illustration

When I die, what happens to my microbiome?

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Side view of a funny cheerful baby girl wearing Santa hat, standing inside a crib in a room during Christmas time.

This week鈥檚 new questions

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Many living earthworms for fishing in the soil, background; Shutterstock ID 1932989285; purchase_order: -; job: -; client: -; other: -

Can worms regenerate if they are cut in half longitudinally?

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An artist's illustration of the longest black hole jet system ever observed. Nicknamed Porphyrion after a mythological Greek giant, these jets span roughly 7 megaparsecs, or 23 million light-years

What would happen if a black hole jet hit the sun or Earth?

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Group of Asian friends having fun enjoying beach camping in summer

Is music an essential part of human evolution? Part 2

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J7JGYD Cuban Rock Iguana, Cyclura nubila, Jardines de la Reina, Cuba

This week鈥檚 new questions

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CY810A Senior / mature man (aged 71) humorous portrait with prominent bushy wild unkempt eyebrows

Why do we start growing lots of ear, nose and eyebrow hair as we age?

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Close up of a spinning globe on black; Shutterstock ID 22230961; purchase_order: -; job: -; client: -; other: -

How long will it be before the rules for leap years need revision?

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Walking highland cattle on sunset, scottish cow; Shutterstock ID 2496920209; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

Why do so many Scottish animals have red fur or hair, such as red squirrel, red deer, Highland cows and red-headed humans? And how do human infants think and communicate before they acquire language?

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Could a huge, prolonged volcanic eruption happen again?

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Is there evidence disproving that we are part of a simulation? Part 2

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This week鈥檚 new questions

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Could there be smaller universes in the particles we know of?

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