system puzzle

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Across
  1. 2. A system that protects the body from bacteria and viruses.
  2. 4. A system that breaks down nutrients that you eat.
  3. 7. A system that helps the body breathe in and out.
  4. 8. A system responsible for providing strength.
Down
  1. 1. Stability while adjusting to changing external conditions in the body.
  2. 3. A system that's your body's central framework.
  3. 5. A tiny living organ is your body.
  4. 6. Parts of a system like the lungs or the heart.