The Alveoli of the Lungs Do Not Contain Air with 20.9

question 224

Multiple Choice

The alveoli of the lungs do not contain air with 20.9% O₂ (i.e., the percentage in dry air) because

• A) we normally do not ventilate our lungs at a high enough rate.
• B) the lungs have too many alveoli to ventilate.
• C) there is dead space in the trachea, bronchi, and lungs.
• D) the trachea and bronchi are too small in volume to contain this amount of O₂.
• E) some O₂ has been exchanged before reaching the alveoli.

---

Definitions:

Interest-Rate Cost-of-Funds Curve

A graphical representation showing the relationship between the interest rates on loans and the total amount of funds loaned by banks.

MB = MC Decision Framework

A decision-making framework where optimal resource allocation occurs when marginal benefits (MB) equal marginal costs (MC).

Marginal Cost Element

An increase in total cost that results from producing one additional unit of a good or service.

Entrepreneurs

Individuals who create, organize, and operate businesses, taking on financial risks in the hope of profit.