Which Cells Are the Main Sites of Gas Exchange

question 17

Multiple Choice

Which cells are the main sites of gas exchange?

• A) A
• B) B
• C) C
• D) D
• E) All of these choices

---

Definitions:

Fixed Costs

Expenses that do not change with the level of production or sales activities within a certain scale, such as rent, salaries, and insurance.

Variable Costs

are expenses that change in proportion to the activity of a business, such as sales volumes, including costs of goods sold and direct labor costs.

Selling Price

The actual price at which a product or service is sold to customers.

Labor Cost

The total amount of financial compensation, benefits, and taxes companies must pay for their employees' work.