When you swallow food, it doesn't just drop down into your stomach. Muscles contract in a wave-like motion to move the food along through the esophagus. This muscle movement is called, peristalsis, or peristaltic waves. These peristaltic waves contract behind the food bolus pushing it along the digestive tract.
B. subcutaneous skin layer
I think the answer is C. They are trying to emotionally avoid the exam by distracting themselves
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