Figure 54.9 -Which of the Following Is Not a Source of Human-Fixed

question 21

Multiple Choice

Figure 54.9
-Which of the following is not a source of human-fixed nitrogen?

• A)industrially produced fertilizers
• B)cultivation of soybeans
• C)combustion of fossil fuels
• D)irrigation agriculture

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Definitions:

Thoracic Cavity

The part of the body known as the chest cavity, which houses the lungs, heart, and other vital organs.

Vitamin D

A fat-soluble vitamin that is essential for maintaining the health of bones and teeth and supports the immune system, often obtained through sunlight exposure or dietary sources.

Severe Burns

Burns that are classified as third-degree (or higher) injuries, affecting the full thickness of the skin and possibly underlying tissues, often requiring specialized medical treatment.

Skin

The body's largest organ, serving as a protective barrier against mechanical impacts, pathogens, and water loss, and involved in temperature regulation.