1. How many times we breathe per minute?

2. The amount of air of respiratory importance reaching into alveoli is?

3. Respiration means?

4. We loose which of these amounts of CO2 per minute?

5. External respiration usually called breathing involves?

6. Because being trapped in 'dead space' which of these amounts of inhaled air does not reach alveoli of our lungs?

7. Our normal O2 intake per minute amounts to?

8. We inhale about which of these amounts of air in one breathe?

9. After each expiration the alveoli of lungs contain which of these amounts of air?

10. Air we inhale has which of the following substances in it?