Minerva the godess of crafts represents the Mentor
It was beneficial because it brought many new foods and livestock to different parts of the world promoting more agriculture
It was detrimental because the Europeans killed over 90% of the Native American population
Hyphen's will be used when a word is hyphenated. Hyphens join words together, while dashes separate them.
I don't believe that any of these are run-on sentences. This is because they all possess some form of punctuation, which creates a small to moderate oause in the sentence, allowing for the person reading to breathe in between, and preventing a run-on sentence.