I would say B because c and d would decrease competition and a would do the same, or just kill the ecosystem.
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Answer:
Digestion of food.
Explanation:
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It’s either the first or second one
I think it’s the first one - the outer cells of the blastocyst
Answer:
Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate). Crystals, in general, are pure substances. Tin, sulfur, and diamond are examples of pure substances that are chemical elements. All elements are pure substances.
Explanation:
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