Answer: D
They often occur spontaneously, because when energy is released during a chemical reaction it does not usually happen slowly.
I would say this is an expository text.
Here is an article that can help.
https://healthblog.uofmhealth.org/heart-health/anatomy-of-a-human-heart
Answer:
A sexual norm can refer to a personal or a social norm. Most cultures have social norms regarding sexuality, and define normal .
Explanation:
hope this helps
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