Question

I need help!

(1) Experts have several theories to explain why people yawn. (2)One explanation is that yawns help boost oxygen levels in the blood. (3)By forcing the body to breathe deeply, yawns increase airflow to the lungs and rush oxygen to the bloodstream. (4)A second theory is that yawns help the body change its level of alertness. (5)It is for this reason yawns happen whether a person is waking up or getting sleepy. (6)Yet another explanation is that yawns, like stretches, give the body exercise. (7)When a person yawns, blood pressure and heart rate gently increase and muscles flex. (8)No matter what the cause for yawning, one thing is clear. (9)Fifty-five percent of the people who read this paragraph will yawn in less than five minutes.

7. The passage contains

a. three major supporting details.

b. four major supporting details.

c. five major supporting details.

Answer 1

a. three major supporting details.

There are three supporting details for the main idea on the theories to explain why people yawn. Each of the supporting details contains a key word or phrase to indicate that they indeed are a main supporting detail. These key words and phrases are "One explanation is...", "A second theory...", and "Yet another explanation...". These all show the supporting detail is contained in the sentence. The last sentences just build and connect to information that has already been introduced.