21. The Immune System - 11! 4부

21. The Immune System / Physical Barriers in First-Line Defenses: Mucous Membrane / 문제 8

문제 8

What is peristalsis?

The release of digestive enzymes

The process of nutrient absorption

The secretion of mucus in the respiratory tract

The rhythmic contraction of muscles to propel contents through the digestive tract