女生小视频

Last Word

Yellow wash scrub sponge placed on wet blue background covered with drops of water in light room during household chores; Shutterstock ID 2167323189; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

Why does a slightly damp sponge absorb water so much better than the same sponge when it is bone dry? And why does Earth have an iron core, rather than one made of another abundant element such as silicon?

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Motion Speed Light in London City; Shutterstock ID 1093994570; purchase_order: -; job: -; client: -; other: -

Is the speed of light in high gravity different from in low gravity?

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2REAK4A world map of african countries and arabian sea, madagascar island and zambia in close up focus

Why is the east coast of Madagascar so straight?

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BNYGBG Astronaut Ed White the First American to Conduct a Spacewalk on Gemini 4 Mission June 3rd 1965 - Manuevering gun in his Right hand and Tether Cable

This week鈥檚 new questions

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Middle-aged woman in glasses fell asleep while reading book at home, female sleeping with open mouth on sofa near coffee table with houseplant in living room. Sleep deprivation; Shutterstock ID 2122133960; purchase_order: -; job: -; client: -; other: -

Are we conscious when we are asleep?

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The surface of Venus, the irregularities of the planet. Elements of this image furnished by NASA. High quality photo; Shutterstock ID 2157724597; purchase_order: -; job: -; client: -; other: -

Could we build a habitable dome on the surface of Venus? (continued)

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Two seagulls above aircraft wing

This week鈥檚 new questions

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The Supermoon rises over houses in Olvera, in the southern Spanish province of Cadiz, July 12, 2014. Occurring when a full moon or new moon coincides with the closest approach the moon makes to the Earth, the Supermoon results in a larger-than-usual appearance of the lunar disk. REUTERS/Jon Nazca (SPAIN - Tags: SOCIETY CITYSCAPE TPX IMAGES OF THE DAY) - GM1EA7D0FC401

When was it first realised that moonlight must be reflected sunlight?

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Ben Lomond ski village and wild kangaroos on a quiet winter's day in Tasmania, Australia; Shutterstock ID 1815999107; purchase_order: -; job: -; client: -; other: -

Would a northern hemisphere 鈥渋ce age鈥� trigger one in the south too?

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Big dog meets small dog; Shutterstock ID 2045462630; purchase_order: -; job: -; client: -; other: -

How do dogs recognise that another animal is also a dog? (continued)

One reader recalls a white terrier鈥檚 excitement on seeing a model of a polar bear in a shop window - showing that dogs don鈥檛 always get this right

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This week鈥檚 new questions

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What would happen to a galaxy if the black hole at its centre left?

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Why did a piece of pink geranium make red flowers after breaking off?

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Given the impact of cats, why don鈥檛 we domesticate more rats? (Part 2)

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