Skin, saliva, and the urinary tract are all considered a first line of defense against foreign elements.

Name: Skin, saliva, and the urinary tract are all considered a first line of defense against foreign elements.
Brand: Quizplus
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Question

Quizplus · Accepted Answer

Skin, saliva, and the urinary tract are all physical barriers that help prevent the entry of foreign elements into the body, which is the first line of defense of the immune system.

Skin, Saliva, and the Urinary Tract Are All Considered a First