What was a common belief among historians in the early 20th century that makes their sources biased

1. a person who does not like gambling or playing the stock market most likely has a high 2. a lamborghini, a playstation 4 pro, and an amazon echo are all examples of a person's instead of things like water and food. 3. revenue - costs = 4. is the most common market structure. 5. media such as magazines (i.e entertainment weekly, time, etc.) and t.v. (i.e. cbs, cw, etc.) make the majority of their money through 6. disney, viacom, and aol time warner are examples of which own a larger number of other businesses in the industry. 7. if zed creates and manages his own business creating and selling teleporters he would be the of this business taking all the risk but receiving all the rewards. 8. razors and printers are example of the business model. 9. wal-mart and best buy both use the business model which allows flexibility and convenience. 10. in the economic system workers and businesses are both and 11. if mattel wants to know if their newest toy will be profitable they will use like focus groups, to determine what consumers want.