The answer is one mystery that still remains unsolved is why we yawn.
and another theory is that when you yawn it sends oxygen to the brain causing your body to be able to stay awake, hence when you are tired and need to stay awake you yawn a lot.
Answer:
D. As Susan entered the airport, she wondered if she was making the right decision.
Explanation:
i took the quiz and got it correct :)
C. is. the correct answer
please let me know if you have any questions about how i answered this question please:)
