Secondly, advocates for year-round school argue that schools will save money because more of them can attend the same schools if they do not attend at the same time.
Which noun BEST replaces the underlined words in the sentence?

eli whitney was an american inventor best known for inventing the cotton gin. this was one of the key inventions of the industrial revolution and shaped the economy of the antebellum south.

dr eric sanderson is a character from the book "a world without us". acording to this story dr sanderson's goal is to determine what manhattan island was in the past, before it became a city. sanderson is an ecologist who is interested in the way manhattan looked like in the 17th century.