What is a rule in a school handbook where an oxford comma is necessary?

The novel begins with a flashback. what do you think is its purpose? what do you learn about the narrator?

The legend of king arthur and the basis of its factuality have drawn a good deal of attention for hundreds of years, from both popular culture as well as academic scholars. consider, now, the consequences of a definitive resolution to the issue of his existence. do you feel that not knowing in this case is perhaps preferred to knowing? what other mysteries might we as a culture prefer to remain unsolved? why?

Read the sentence. the great wave was inexpensive to purchase, costing only about the same as a double of noodles. since lots of copies could be printed and still look good, it made loads of money. which best revises this sentence to create a more formal style and tone? *the great wave was as cheap as buying a double of noodles. since lots of copies could be made and still look great, people started making piles of money. *the great wave was inexpensive to purchase, costing about the same as a double of noodles. since mass quantities could be produced and still look exquisite, it became highly profitable to sell. *the great wave cost next to nothing, practically the same as a double of noodles. since mass quantities could be produced and still look awesome, it became highly profitable to sell. *the great wave was inexpensive to purchase, similar to buying a double of noodles. since lots of copies could be made that still looked amazing, those who sold it made tons of money.