Q: A diet rich in calcium and what vitamin may reduce the risk of osteoporosis and related bone fractures? Choices: - niacin - vitamin A - vitamin C - vitamin d A:
vitamin d
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Q: What man-made devices in space are used to observe the earth's surface? Choices: - crystals - telescopes - sensors - satellites A:
satellites
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Q: What is unique and found in all living things because it can form up to four covalent bonds between atoms or molecules? Choices: - hydrogen - oxygen - potassium - carbon A:
carbon
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Q: Which organ secretes estrogen? Choices: - the testes - the thyroid - the kidney - the ovaries A:
the ovaries
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