Why is using the Purchases Returns and Allowances account preferred to crediting these transactions to Purchases?

Which feature transfers a slide show into a word-processing document?

Self-interest achieve society’s economic goals because producers know which goods consumers want the most. as consumers and producers exercise their freedom to act in their own self-interest, markets will produce the desired goods at the lowest possible cost. consumers and producers both operate based on society’s economic goals. consumers know which goods can be produced at the lowest cost. there is a wide variety of desired goods and services in a market system because producers determine what to produce. consumers change their minds frequently. there is always a need to produce something new and improved. individual wants are diverse. what is produced is ultimately determined by consumers, because if the goods offered are not what consumers want, consumers will not buy them. producers, because they are driven by profits. producers, because they determine what to produce. consumers, because they participate in marketing surveys.

Google started as one of many internet search engines, amazon started as an online book seller, and ebay began as a site where people could sell used personal items in auctions. these firms have grown to be so large and dominant that they are facing antitrust scrutiny from competition regulators in the us and elsewhere. did these online giants grow by fairly beating competition, or did they use unfair advantages? are there any clouds on the horizon for these firms -- could they face diseconomies of scale or diseconomies of scope as they continue to grow? if so, what factors may limit their continued growth?