Ques:Q: What causes rivers to always flow downhill? Choices: - slope - pressure - diffusion - gravity A:

Ans:gravity
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Ques:Q: What are the two main parts of the human nervous system? Choices: - lungs, brain - lungs, spinal cord - brain, heart - brain, spinal cord A:

Ans:brain, spinal cord
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Ques:Q: What is the term for the distance between two corresponding points on adjacent waves? Choices: - arc wave - variation - bandwidth - wavelength A:

Ans:wavelength
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Ques:Q: Why does ice wedging occur? Choices: - water melts - water freezes - water evaporates - water expands A:

Ans:
water expands
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