Answer:
In the 1960s, scientists found evidence that new material is indeed erupting along mid-ocean ridges. The scientists dived to the ocean floor in Alvin, a small submarine built to withstand the crushing pressures four kilometers down in the ocean. In a ridge’s central valley, Alvin’s crew found strange rocks shaped like pillows or like toothpaste squeezed from a tube. Such rocks form only when molten material hardens quickly after erupting under water. These rocks showed that molten material has erupted again and again along the mid-ocean ridge.
When scientists studied patterns in the rocks of the ocean floor, they found more support for sea-floor spreading. You read earlier that Earth behaves like a giant magnet, with a north pole and a south pole. Surprisingly, Earth’s magnetic poles have reversed themselves many times during Earth’s history. The last reversal happened 780,000 years ago. If the magnetic poles suddenly reversed themselves today, you would find that your compass needle points south.
Explanation:
I found this somewhere.
True! because if you have more than one variable, you aren’t going to know which variable changed the dependent variable.
Answer:
<h2> AA
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Explanation:
1. A restriction enzyme, restriction endonuclease, an enzyme that cleaves DNA into small fragments at or near specific recognition sites (different restriction enzyme has different restriction site) within molecules known as restriction sites.
2. Restriction enzymes are found in archaea and bacteria.
3 And in bacteria and archaea they provide a defence mechanism against invading viruses.
4. Each restriction enzyme cut at the specific site, because each restriction enzyme have specific recognition site.
The answer is; C & E
Building a dam alters the water regime down the dam. The dam also affects fish migration along the river, alters the transportation of sediments by the river downstream, and changes temperatures within the local environment of the dam. These changes, however, the subtle effect the ecosystem around the dam and down the river. The potential energy of the water held by the dam is, however, high and used to produce more electricity.