Q: All living things require what, which most ecosystems obtain from the sun? Choices: - oxygen - water - heat - energy A:
energy

Q: Arteries carry oxygenated blood away from the heart, what carries un-oxygenated blood back to the heart? Choices: - glands - intestines - lungs - veins A:
veins

Q: Q: Arteries have thinner wall layers and valves and move blood by the action of skeletal what? Choices: - marrow - collagen bands - hormones - muscle A:
A: muscle

Question: Q: What is caused by bodies sliding over rough surfaces? Choices: - heat loss - tension - vibration - friction A:
Answer: friction

*Question*
Q: What is the diffusion of water known as? Choices: - evaporation - electrolysis - hemostasis - osmosis A:
**Answer**
osmosis

(Question)
Q: In contrast to metals, electrical insulators are materials that conduct electricity poorly because their valence bands are what? Choices: - empty - large - half-full - full A:
(Answer)
full