Question

why are yawns contagious? we asked a scientist by teresa carey there is no scientific consensus on why we yawn one theory argues that when humans are tired, we stop taking deep breaths, which causes a build - up of carbon dioxide in the body. said douglas parham, a speech scientist at wichita state university, a yawn might be a special kind of respiration. parham said it builds up oxygen quickly while expelling carbon dioxide even more than a deep breath use the passage to answer the question what is the purpose of the transitions one theory and other proposals in this excerpt? (1 point) to point out a specific example of a general phenomenon to draw a contrast between two ideas to group together explanations to the same question to show a cause - effect relationship

Explanation:

The transitions "One theory" and "other proposals" are used to introduce different ideas and explanations about why we yawn. They group together various explanations for the same phenomenon of yawning.

Answer:

to group together explanations to the same question