Originally posted by mugabe
Why not? "Water, salt, macaroni, and cheese."
I'd use a hyphen in the above sentence, though; "Ayers Rock - the world’s largest monolith, and the Great Barrier Reef - the world's largest coral reef."
Nope - actually the best way is to put the two facts in separate sentences.
you would you use if you repeated 'and' but this would be grammitically incorrect and only used for speech, eg. The child was so excited as he desribed his day to his father: "There was fireworks, and rides, and food, and animals, and I got to eat fairy floss, and ...."
Generally the commas between each of the nouns in your 1st sentence replaces 'and' therefore you use an 'and' before the last noun but without the comma.
However, yr 2nd sentence the it partly correct in using the comma, but the sentences alone are incomplete. If you use
"Ayers Rock - the world's largest monolith" it requires further information, eg. "The most visited attraction in Australia is Ayers Rock - the world's ..."
or
"Ayers Rock, the world's largest monolith, is the most visited tourist attraction in Australia..."
The same applies with 'or', eg. black, white or red