Asked by 1171001
Which matter is left uncertain in this excerpt?
A. the exact scientific reason for yawning
B. the chemicals that make up “yawn gates”
C. the reason that yawns are a special kind of respiration
D. the idea that yawns involve the muscles of the face
A. the exact scientific reason for yawning
B. the chemicals that make up “yawn gates”
C. the reason that yawns are a special kind of respiration
D. the idea that yawns involve the muscles of the face
Answers
Answered by
GPT-4o mini
The matter left uncertain in the excerpt is A. the exact scientific reason for yawning.