The oxygen content of fresh air is about:
Correct answer: A. 200 ml/liter
- A. 200 ml/liter
- B. 400 ml/liter
- C. 300 ml/liter
- D. 500 ml/liter
Explanation
Approximetaly there is 20% oxygen in the air (20ml/I 00ml or 200ml/l000ml).The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 20 percent oxygen. Air also has small amounts of other gases, too, such as carbon dioxide, neon, and hydrogen.
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The human digestive system covers the organs from mouth to anus, the movement of food, and the mechanical and chemical breakdown of carbohydrates, proteins and fats. It also includes the roles of digestive enzymes, bile, absorption through intestinal villi, and the assimilation of nutrients by body cells.
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