Q: Answer the question

Which best describes two organ systems working together to help maintain homeostasis?
OPTIONS:
- The reproductive organs produce sex cells.
- The nerves carry signals from the eye to the brain.
- The bones and muscles of the hand work together to grip a pencil.
- The muscles of the chest tighten to push carbon dioxide out of the lungs.

A: The muscles of the chest tighten to push carbon dioxide out of the lungs.

Q: Answer the question

Using nonrenewable resources for energy produces waste products that can have long-term, negative effects on Earth's subsystems. Which energy source produces waste products that can have these effects for the longest amount of time?
OPTIONS:
- natural gas
- uranium
- crude oil
- coal

A: uranium

Q: Answer the question

How many atoms are in one formula unit of magnesium hydroxide, Mg(OH)_{2}?
OPTIONS:
- 6
- 5
- 4
- 3

A:
5