Question: Q: What force provides resistance whenever two surfaces are in contact? Choices: - vibration - tension - rotation - friction A:
Answer: friction

Question: Q: The testes produce what hormone? Choices: - dopamine - insulin - estrogen - testosterone A:
Answer: testosterone

Question: Q: How are aquatic biomes often classified? Choices: - depth - amount of life - amount of light - amount of salt A:
Answer:
amount of salt