修辞目的题做法解析

1. 修辞目的题做法解析 主讲人：叶磊华

2. Rhetorical Purpose Questions Rhetoric is the art of speaking or writing effectively Three ways to recognize rhetorical questions: 1. The author discusses X in paragraph 2 in order to … 2. Why does the author mention X? 3. The author uses X as an example of… 4. What is the purpose …

3. Paragraph 1: Petroleum, consisting of crude oil and natural gas, seems to originate from organic matter in marine sediment. Microscopic organisms settle to the seafloor and accumulate in marine mud. The organic matter may partially decompose, using up the dissolved oxygen in the sediment. As soon as the oxygen is gone, decay stops and the remaining organic matter is preserved. Paragraph 2: Continued sedimentation—the process of deposits’ settling on the sea bottom—buries the organic matter and subjects it to higher temperatures and pressures, which convert the organic matter to oil and gas. As muddy sediments are pressed together, the gas and small droplets of oil may be squeezed out of the mud and may move into sandy layers nearby. Over long periods of time (millions of years), accumulations of gas and oil can collect in the sandy layers. Both oil and gas are less dense than water, so they generally tend to rise upward through water-saturated rock and sediment. In paragraphs 1 and 2, the author’s primary purpose is to describe how petroleum is formed explain why petroleum formation is a slow process provide evidence that a marine environment is necessary for petroleum formation show that oil commonly occurs in association with gas

4. Paragraph 2: How might this inability to recall early experiences be explained? The sheer passage of time does not account for it; adults have excellent recognition of pictures of people who attended high school with them 35 years earlier. Another seemingly plausible explanation—that infants do not form enduring memories at this point in development—also is incorrect. Children two and a half to three years old remember experiences that occurred in their first year, and eleven month olds remember some events a year later. Nor does the hypothesis that infantile amnesia reflects repression—or holding back—of sexually charged episodes explain the phenomenon. While such repression may occur, people cannot remember ordinary events from the infant and toddler periods either. Paragraph 3: Three other explanations seem more promising. What purpose does paragraph 2 serve in the larger discussion of children’s inability to recall early experiences? To argue that theories that are not substantiated by evidence should generally be considered unreliable To argue that the hypotheses mentioned in paragraph 2 have been more thoroughly researched than have the theories mentioned later in the passage To explain why some theories about infantile amnesia are wrong before presenting ones more likely to be true To explain why infantile amnesia is of great interest to researchers

5. 看本句 The latter two sources are limited to those few areas where surface water seeps down through underground faults or fractures to reach deep rocks heated by the recent activity of molten rock material. The world‘s largest supply of natural steam occurs at The Geysers, 120 kilometers north of San Francisco, California. In the 1990s enough electricity to meet about half the needs of San Francisco was being generated there. This facility was then in its third decade of production and was beginning to show signs of decline, perhaps because of over development. • In paragraph 3, why does the author mention that in the 1990s The Geysers was in its third decade of production? • To provide the historical context of the geothermal production of electricity in the United States • To imply that The Geysers was the first geothermal site to be put into production in California • To help explain the signs of decline shown by The Geysers • To explain why 70 new geothermal sites were put into electricity production in the late 1990s

6. 看前一句 。。。One type of seed-bearing plant, the angiosperm, includes all forms of blooming vegetation. In the angiosperm the seeds are wrapped in an additional layer of covering. Some of these coats are hard–like the shell of a nut–for extra protection. Some are soft and tempting, like a peach or a cherry. 。。。 9. Why does the author mention “a nut”, “a peach”, and “a cherry”? ○To indicate that some seeds are less likely to survive than others ○To point out that many angiosperms can be eaten ○To provide examples of blooming plants ○To illustrate the variety of coverings among angiosperm seeds

7. 看本段 The numbers of deer have fluctuated markedly since the entry of Europeans into Puget Sound country. The early explorers and settlers told of abundant deer in the early 1800s and yet almost in the same breath bemoaned the lack of this succulent game animal. Famous explorers of the north American frontier, Lewis and Clark arrived at the mouth of the Columbia River on November 14, 1805, in nearly starved circumstances. They had experienced great difficulty finding game west of the Rockies and not until the second of December did they kill their first elk. To keep 40 people alive that winter, they consumed approximately 150 elk and 20 deer. And when game moved out of the lowlands in early spring, the expedition decided to return east rather than face possible starvation. 。。。 The author tells the story of the explorers Lewis and Clark in paragraph 3 in order to illustrate which of the following points? ○The number of deer within the Puget Sound region has varied over time. ○Most of the explorers who came to the Puget Sound area were primarily interested in hunting game. ○There was more game for hunting in the East of the United States than in the West. ○Individual explorers were not as successful at locating games as were the trading companies.

8. 隐含条件 Paragraph 3: Watt‘s steam engine soon showed what it could do. It liberated industry from dependence on running water. The engine eliminated water in the mines by driving efficient pumps, which made possible deeper and deeper mining. The ready availability of coal inspired William Murdoch during the 1790s to develop the first new form of nighttime illumination to be discovered in a millennium and a half。。。 In paragraph 3, the author mentions William Murdoch’s invention of a new form of nighttime illumination in order to indicate one of the important developments made possible by the introduction of Watt‘s steam engine make the point that Watt‘s steam engine was not the only invention of importance to the Industrial Revolution illustrate how important coal was as a raw material for the Industrial Revolution provide an example of another eighteenth-century invention that used steam as a power source

9. Deeper and deeper mining

10. 隐含条件 The picture of Teotihuacán that emerges is a classic picture of positive feedback among obsidian mining and working, trade, population growth, irrigation, and religious tourism. The thriving obsidian operation, forexample, would necessitate more miners, additional manufacturers of obsidian tools, and additional traders to carry the goods to new markets. All this led to increased wealth, which in turn would attract more immigrants to Teotihuacán. 。。。 In paragraph 6, the author discusses “The thriving obsidian operation” in order to explain why manufacturing was the main industry of Teotihuacán give an example of an industry that took very little time to develop in Teotihuacán Illustrate how several factors influenced each other to make Teotihuacán a powerful and wealthy city explain how a successful industry can be a source of wealth and a source of conflict at the same time

11. Paragraph 2:  These Kinetoscope arcades were modeled on phonograph parlors, which had proven successful for Edison several years earlier. In the phonograph parlors, customers listened to recordings through individual ear tubes, moving from one machine to the next to hear different recorded speeches or pieces of music. The Kinetoscope parlors functioned in a similar way. Edison was more interested in the sale of Kinetoscopes (for roughly $1,000 apiece) to these parlors than in the films that would be run in them (which cost approximately $10 to $15 each). He refused to develop projection technology, reasoning that if he made and sold projectors, then exhibitors would purchase only one machine-a projector-from him instead of several. The author discusses phonograph parlors in paragraph 2 in order to explain Edison‘s financial success describe the model used to design Kinetoscope parlors contrast their popularity to that of Kinetoscope parlors illustrate how much more technologically advanced Kinetoscope parlors were

12. 。。。Another explanation for the focus on animals might be that these people sought to improve their luck at hunting. This theory is suggested by evidence of chips in the painted figures, perhaps made by spears thrown at the drawings. But if improving their hunting luck was the chief motivation for the paintings, it is difficult to explain why only a few show signs of having been speared. Perhaps the paintings were inspired by the need to increase the supply of animals. Cave art seems to have reached a peak toward the end of the Upper Paleolithic period, when the herds of game were decreasing. Why does the author mention that Upper Paleolithic cave art seemed to have “reached a peak toward the end of the Upper Paleolithic period, when the herds of game were decreasing”? To argue that Upper Paleolithic art ceased to include animals when herds of game became scarce To provide support for the idea that the aim of the paintings was to increase the supply of animals for hunting To emphasize the continued improvement in the quality of cave art throughout the Upper Paleolithic period To show the direct connection between the decrease in herds of game and the end of the Upper Paleolithic period

13. Paragraph 2: …The onrushing water arising from these flash floods likely also formed the odd teardrop-shaped “islands” (resembling the miniature versions seen in the wet sand of our beaches at low tide) that have been found on the plains close to the ends of the outflow channels. Judging from the width and depth of the channels, the flow rates must have been truly enormous—perhaps as much as a hundred times greater than the 105 tons per second carried by the great Amazon river. Flooding shaped the outflow channels approximately 3 billion years ago, about the same times as the northern volcanic plains formed. In paragraph 2, why does the author include the information that 105 tons of water flow through the Amazon river per second? To emphasize the great size of the volume of water that seems to have flowed through Mars’ outflow channels To indicate data used by scientists to estimate how long ago Mars’ outflow channels were formed To argue that flash floods on Mars may have been powerful enough to cause tear-shaped “islands” to form To argue that the force of flood waters on Mars was powerful enough to shape the northern volcanic plains

14. Paragraph 4: Reduction in numbers of game should have boded ill for their survival in later times. A worsening of the plight of deer was to be expected as settlers encroached on the land, logging, burning, and clearing, eventually replacing a wilderness landscape with roads, cities, towns, and factories. No doubt the numbers of deer declined still further. Recall the fate of the Columbian white-tailed deer, now in a protected status. But for the black-tailed deer, human pressure has had just the opposite effect. Wildlife zoologist Helmut Buechner(1953), in reviewing the nature of biotic changes in Washington through recorded time, says that “since the early 1940s, the state has had more deer than at any other time in its history, the winter population fluctuating around approximately 320,000 deer (mule and black-tailed deer), which will yield about 65,000 of either sex and any age annually for an indefinite period.” Why does the author ask readers to recall “the fate of the Columbian white-tailed deer” in the discussion of changes in the wilderness landscape? To provide support for the idea that habitat destruction would lead to population decline To compare how two species of deer caused biotic changes in the wilderness environment To provide an example of a species of deer that has successfully adapted to human settlement To argue that some deer species must be given a protected status

15. Paragraph 2: When crayfish are kept continuously in the dark, even for four to five months, their compound eyes continue to adjust on a daily schedule for daytime and nighttime vision. Horseshoe crabs kept in the dark continuously for a year were found to maintain a persistent rhythm of brain activity that similarly adapts their eyes on a daily schedule for bright or for weak light. Like almost all daily cycles of animals deprived of environmental cues, those measured for the horseshoe crabs in these conditions were not exactly 24 hours. Such a rhythm whose period is approximately—but not exactly—a day is called circadian. For different individual horseshoe crabs, the circadian period ranged from 22.2 to 25.5 hours. A particular animal typically maintains its own characteristic cycle duration with great precision for many days. In paragraph 2, why does the author mention that the period for different horseshoe crabs ranges from 22.2 to 25.5 hours? To illustrate that an animal‘s internal clock seldom has a 24-hour cycle To argue that different horseshoe crabs will shift from daytime to nighttime vision at different times To illustrate the approximate range of the circadian rhythm of all animals To support the idea that external cues are the only factors affecting an animal's periodic behavior

16. …The data showed that yawning tended to occur about 15 minutes before a period of increased behavioral activity. Yawning bore no relationship to sleep patterns, however. This accords with anecdotal evidence that people often yawn in situations where they are neither tired nor bored, but are preparing for impending mental and physical activity. Such yawning is often referred to as “incongruous” because it seems out of place, at least on the tiredness view: soldiers yawning before combat, musicians yawning before performing, and athletes yawning before competing. Their yawning seems to have nothing to do with sleepiness or boredom—quite the reverse—but it does precede a change in activity level. • Why does the author mention “soldiers yawning before combat, musicians yawning before performing, and athletes yawning before competing”? • To argue that just the expectation of physical activity can make some people feel tired • To explain how the view that people yawn because they are tired accounts for yawning before stressful situations • To support the view that yawning helps prepare a person for mental or physical exertion • To provide anecdotal evidence that conflicts with the experience of the volunteers in the study

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