should:Pluto was known as a planet for 75 years. This means that most people already knew it as a planet, and would be extremely confused. All of the books about planets would be inaccurate and changed. Not all people can access brand new books, leading to inaccurate information.
shouldn't: The same reason that it was unclassified as a planet. It does not adhere to all of the rules of being a planet. It is not completely round and does not have a round orbit around the sun. Pluto does not have every requirement to be a real planet, and therefor, it would be incorrect to have it classified wrongly.
The heart must beat faster during exersise because by increasing the heart rate the body is able to increase cardiac output and deliver the necessary blood flow to the mucles
