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Agata [3.3K]
3 years ago
8

3. When (what year) were stone tools first used?

Biology
1 answer:
Dima020 [189]3 years ago
4 0
Stone tools we’re first used around 3,300 BCE
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Which statement best describes the relationship between photosynthesis and cellular respiration
grandymaker [24]

Answer:

Photosynthesis removes carbon from the atmosphere, and cellular respiration releases carbon from the atmosphere

Explanation:

This is the role of the reactions in the carbon cycle.

8 0
3 years ago
Individual bones are organs.<br> A. True<br><br> B. False
german

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a

Explanation:

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The water level at the beach changes during the day. What causes the different water levels?
dexar [7]

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C. The moon's gravitational pull and Earth's rotation

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The moon's gravitational pull generates something called the tidal force. The tidal force causes Earth—and its water—to bulge out on the side closest to the moon and the side farthest from the moon. These bulges of water are high tides.

Hope this helped

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3 0
3 years ago
if an element has a half-life of 30 million years and there is 12.5% of it remaining in a rock, how old is that rock
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The half-life of a substance is the amount of time it takes for half of that substance to decay. However, after two half-lives, half of the half remaining will decay, leaving you with one quarter of the original substance.

So, after 1 million years you will have 50% of the original substance remaining.

And, after 2 million years you will have 25% of the original substance remaining.

After 3 million years you will have 12.5% of the original substance remaining.

And after 4 million years you will have 6.25% of the original substance remaining.

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If proven to be true, a hypothesis can become a theory, a theorem, or a law. Since her hypothesis is proven to be true, it is no longer a hypothesis.
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