For nearly a century, two United States governmental agencies, the United States Army Corps of Engineers and the Bureau of Reclamation, have constructed dams to store water and to generate electricity. Building these dams provided cheap electricity, created jobs for workers, stimulated regional economic development, and allowed farming on lands that would otherwise be too dry. But not everyone agrees that big dam projects are entirely beneficial. Their storage reservoirs stop the flow of rivers and often submerge towns, farms, and historic sites. They prevent fish migrations and change aquatic habitats essential for native species.
The tide may have turned, in fact, against dam building. In 1998 the Army Corps announced that it would no longer be building large dams. In the few remaining sites where dams might be built, public opposition is so great that getting approval for projects is unlikely. Instead, the new focus may be on removing existing dams and restoring natural habitats. In 1999 Bruce Babbitt, then the United States interior secretary, said, ―Of the 75,000 large dams in the United States, most were built a long time ago and are now obsolete, expensive, and unsafe. They were built with no consideration of the environmental costs. As operating licenses come up for renewal, dam removal and habitat restoration to original stream flows will be among the options considered.‖
The first active hydroelectric dam in the United States to be removed against the wishes of its owners was the 162-year-old Edwards Dam, on the Kennebec River in Augusta, Maine. For many years, the United States Fish and Wildlife Service had advocated the removal of this dam, which prevented migration of salmon, shad, sturgeon, and other fish species up the river. In a precedent-setting decision, the Federal Energy Regulatory Commission ordered the dam removed after concluding that the environmental and economic benefits of a free-flowing river outweighed the electricity generated by the dam. In July 1999 the dam was removed and restoration work began on wetlands and stream banks long underwater.
The next dams likely to be taken down are the Elwha and Glines Dams on the Elwha River in Olympic National Park in the state of Washington. Built nearly a century ago to provide power to lumber and paper mills in the town of Port Angeles, these dams blocked access to upstream spawning beds for six species of salmon on what once was one of the most productive salmon rivers in the world. Simply removing the dams will not restore the salmon, however. Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there now are only concrete walls holding back still water and deep beds of muddy deposits. Removing the mud, uncovering gravel beds where fish spawn, and finding suitable salmon types to rebuild the population is a daunting task. Congress will have to appropriate somewhere around $300 to $400 million to remove these two relatively small dams and rehabilitate the area.
Environmental groups, encouraged by these examples, have begun to talk about much more ambitious projects. Four giant dams on the Snake River in Washington State, for example, might be removed to restore salmon and steelhead fish runs to the headwaters of the Columbia River. The Hetch Hetchy Dam in Yosemite National Park might be taken down to reveal what John Muir, the founder of the prestigious environmental organization Sierra Club, called a valley ―just as beautiful and worthy of preservation as the majestic Yosemite.‖ Some groups have even suggested removing the Glen Canyon Dam on the Colorado River. In each of these cases, powerful interests stand in opposition. These dams generate low-cost electricity and store water that is needed for agriculture and industry. Local economies, domestic water supplies, and certain types of recreation all would be severely impacted by destruction of these dams.
How does one weigh the many different economic, cultural, and aesthetic considerations for removing or not removing these dams? Do certain interests, such as the rights of native people or the continued existence of native species of fish or wildlife, take precedence over economic factors, or should this be a utilitarian calculation of the greatest good for the greatest number? And does that number include only humans or do other species count as well?
1. According to paragraph 1, building dams was beneficial in each of the following ways EXCEPT
A. increasing the amount of land that could be used for farming
B. strengthening local economies
C. increasing the availability of low-cost electricity
D. expanding the aquatic habitats of native species
2. According to paragraph 2, the likelihood that new dams will be built has decreased because
A.construction costs have increased enormously
B. safety standards have become much higher
C. public opposition to dam construction has increased
D. at most suitable sites an existing dam would have to be removed first
3. The word "obsolete " in the passage is closest in meaning to
C. out of date
4. Paragraph 2 supports which of the following ideas about operating licenses for large dams?
A.Since 1999 licenses have been renewed only for small dams.
B. Before 1999, owners applying for a license renewal were more likely to have their applications than they were after that date.
C. Strong public opposition to their renewal was common even before 1999, but it was based on safety considerations, not on environmental ones.
D. The environmental cost of dams has been a minor consideration in license renewal applications since 1999.
5. According to paragraph 3, why did the United States Fish and Wildlife Service want the Edwards Dam removed?
A.Because the age of the dam made it unsafe
B. Because the dam was negatively affecting various species of fish
C. Because the dam had caused wetlands to form
D.Because the dam no longer provided economic benefits
6. Paragraph 3 suggests that one main consideration for keeping the Edwards Dam was
A.the electricity it generated
B. the length of time it had been in operation
C. the high cost of removing it
D. the fact that removing it would set a bad example
7. According to paragraph 4, why would removing the Elwha and Glines dams not be enough to restore salmon to the Elwha River?
A.They are not the only dams on the Elwha River.
B. The lumber and paper mills in Port Angeles also block access to upstream spawning beds.
C. Too many species of salmon are competing for survival in one river.
D. The dams have left the river’s spawning beds in an unusable condition.
8. The word "suitable " in the passage is closest in meaning to
9. The word "ambitious " in the passage is closest in meaning to
A. impressive but difficult to achieve
B.dangerous and require considerable planning
C. complex and unlikely to be complete
D. greatly needed
10. According to paragraph 5, why do environmental groups want the Hetch Hetchy Dam removed?
A.To restore salmon and steelhead runs to the Snake River
B. To allow access to the headwaters of the Columbia River
C. To increase the size of Yosemite National Park
D. To restore a valley to its original beauty
11. The phrase "take precedence over " in the passage is closest in meaning to
B. have greater importance than
C. get included among
12. What is the role of paragraph 6 in the passage?
A.To propose a method for deciding whether a given dam should be removed
B. To emphasize the complexity of the issues involved in deciding what should be done about dams
C. To suggest that the recent tendency not to build new dams may be wrong
D. To sum up the points made earlier in the passage about the advantages and disadvantages of removing dams
Paragraph 4 The next dams likely to be taken down are the Elwha and Glines Dams on the Elwha River in Olympic National Park in the state of Washington. Built nearly a century ago to provide power to lumber and paper mills in the town of Port Angeles, these dams blocked access to upstream spawning beds for six species of salmon on what once was one of the most productive salmon rivers in the world. Simply removing the dams will not restore the salmon, however. ■ Where 50-kilogram king salmon once fought their way up waterfalls to lay their eggs in gravel beds, there now are only concrete walls holding back still water and deep beds of muddy deposits. ■ Removing the mud, uncovering gravel beds where fish spawn, and finding suitable salmon types to rebuild the population is a daunting task. ■ Congress will have to appropriate somewhere around $300 to $400 million to remove these two relatively small dams and rehabilitate the area. ■
13. Look at the four squares [■] that indicate where the following sentence can be added to the passage.
But aside from the technical challenges, the project will also pose a serious financial challenge.
Where would the sentence best fit?
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Drag your choices to the spaces where they belong. To review the passage, click on View Text.
Many dams were built in the United States during the last century, and they provided a broad range of economic benefits. ● ● ●
1.Until recently, the emphasis in dam building was on the economic benefits
of low-cost energy and water that dams provided, but more attention is now being paid to the damage they cause.
2.Environmental groups now have a very good chance of forcing the removal of two major dams, the Glen Canyon Dam on the Colorado and the Hetch Hetchy Dam in Yosemite.
3.The removal of dams remains controversial because of high restoration costs, loss of low-cost electricity, and the loss of water storage facilities.
4.Since the late 1990s, the government has stopped building large dams, instead focusing on removing existing dams and restoring natural habitats.
5.Until recently, the main reason for removing dams was to restore salmon runs, but it is now recognized that a more important reason to remove dams is that they are no longer safe.
6.Although the U. S. government originally planned to remove the Elwha and Glines Dams in Washington, the enormous expense of removal has resulted in a postponement of this effort.
托福阅读答案 DCCBB ADCAD BBC 134