Q: What term refers to the friction of fluid, within itself and its surroundings? Choices: - elasticity - volume - salinity - viscosity A:
viscosity

Q: What substances are secreted by specialized cells usually located in endocrine glands? Choices: - lipids - protein - acid - hormones A:
hormones

Q: Knees and elbows are examples of what part of the skeletal system? Choices: - cartilage - muscles - nerves - joints A:
joints