What are the three main purposes of money?

Money is a unit of account, it's a store of value, and  a medium of exchange  

Hope this helps

b. a single paragraph.

a paragraph is a series of sentences that are organized and make sense, and are all related to a single topic . almost every piece of writing you do that is longer than a few sentences should be organized into paragraphs. this is because paragraphs show a reader where the subdivisions of an essay begin and end, and thus the reader see the organization of the essay into subjects in order to be able to understand its main points.

answer; niosh, the national institute for occupational safety and health;