1. D: The Neolithic period, during which humans transitioned from hunting and gathering to settled agriculture, began between 5,000 and 25,000 years ago. Most archaeologists put the beginning of the Neolithic Revolution at 10,000 to 12,000 years ago, and it is estimated to have ended about 5,000 years ago with the emergence of early civilizations like that in Mesopotamia.
2. D: The Mesopotamian civilization represented a significant development in human history because it was the first urban society. Settled agriculture had developed several thousand years earlier with the Neolithic Revolution, and iron use did not begin until after the peak of the Mesopotamian civilization. The Code of Hammurabi was developed in Babylon.
3. B: It is true that the asthenosphere is hotter and more fluid than the lithosphere. The asthenosphere, also called the upper mantle, is the hot, fluid layer of the Earth’s mantle upon which the lithosphere, or crust, is situated. Heat is transferred within the asthenosphere through a process called convection, which sometimes causes movement in the tectonic plates that make up the lithosphere.
4. C: Overgrazing and deforestation directly contribute to soil erosion by destroying the natural groundcover that normally prevents soil from being washed and blown away. These activities can ultimately result in desertification, which renders land unsuitable for agriculture.
5. C: The main manmade cause of “dead zones” in portions of oceans and lakes that normally host abundant aquatic life is the use of chemical fertilizers. These fertilizers, which are high in nitrogen and phosphorous, enter lakes and rivers in water runoff and become concentrated in certain areas. This concentration, called eutrophication, eventually depletes the water’s oxygen levels and renders it incapable of supporting life.
6. C: The increasing popularity of American fast food restaurant chains in other countries exemplifies cultural diffusion. Diffusion occurs when specific cultural practices of one social group are selectively and voluntarily adopted by another group.
7. D: A foraging society is likely to have up to 100 percent of its working-age population engaged in food production. In contrast, societies that use intensive agriculture typically have less than ten percent of their adult population engaged in food production. In pastoral and horticultural societies, regardless of economic system, roughly 40 to 70 percent of the population is engaged in food production.
8. D: Advances in technology were applied not only to industrial production, but also to farming machinery. Farmers could then supply larger amounts of food to urban workers at lower prices. Farming was not abandoned in favor of industry (a). The many additional workers in cities needed food that they did not grow, so there was an even greater market for farming. This did not mean that farming took precedence over industry (b). Both fields increased during the 19th century, and they complemented one another. Specialization and mechanization were processes applied to both farming and industry. At this time, they were not applied more to farming or industry.
9. B: Harvested stormwater can be used for landscape irrigation as well as other purposes, such as fire suppression, toilet and urinal flushing, and custodial uses. This water is considered nonpotable, and cannot be used for drinking, cooking, or hygiene purposes.
10. B: Unemployment leads to lost productivity because people who would be productive if employed (thus contributing to economic growth) are not economically productive when they do not have work. Option A can be rejected because high unemployment is not typically thought to be a central cause of inflation; rather, high levels of unemployment might instead contribute to deflation (an overall decrease in prices). Option C can be rejected because unemployment would tend to have the effect of decreasing aggregate demand rather than increasing it, simply because fewer people would have money with which to make purchases. Option D can be rejected because unemployment is less likely to increase aggregate supply than to reduce it (fewer people working means fewer people producing goods and services).