The Tiny Air Sacs That Act as the Primary Site

question 50

Multiple Choice

The tiny air sacs that act as the primary site of gas exchange are termed _____.

• A) pharynx
• B) lungs
• C) trachea
• D) alveoli
• E) vocal chords

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Definitions:

Marginal Cost

is the cost incurred by producing one additional unit of a product or service.

Profits

The financial gain made in a transaction or operation, calculated as the difference between revenue and expenses.

Firm

A business organization, such as a corporation or partnership, that sells goods or services in exchange for revenue.

Profit-Maximizing Firm's Output

The output level at which a firm achieves the maximum possible profit, typically where marginal cost equals marginal revenue.