Respiratory system

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Across
  1. 3. ensures that the air can pass through also known as the windpipe
  2. 5. oxygen moves from the ______ into the capillary and blood
Down
  1. 1. muscle expands and contracts, letting air into and out of the lungs
  2. 2. brings oxygen into the lungs
  3. 4. takes in air from the environment and warms, moistens and filters the air
  4. 6. exchanges oxygen and carbon dioxide