The answer is D. Isotopes.
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Answer:
The correct answer is A. The sun is the energy source of the surface currents in the ocean
Answer:
I would say it's B. But just in case here is some information if I'm wrong.
Explanation:
Igneous rocks are very dense and hard. They may have a glassy apprearance. Metamorphic rocks may also have a glassy appearance. You can distinguish these from igneous rocks based on the fact that metamorphic rocks tend to be brittle, lightweight, and an opaque black color.
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