D

Dhruva Jagannath • 660 Points
Invincible

Q. Which gas in Earth's atmosphere is essential for human respiration?

  • (A) Nitrogen
  • (B) Carbon dioxide
  • (C) Oxygen
  • (D) Hydrogen
Explanation by: Dhruva Jagannath
Oxygen makes up about 21% of Earth's atmosphere and is necessary for human and animal respiration.

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