Official21托福阅读Passage1Geothermal Energy文本+题目原文+答案解析【雷哥托福】2019-02-20 13:58:46 发布 来源：雷哥托福
Earth’s internal heat, fueled by radioactivity, provides the energy for plate tectonics and continental drift, mountain building, and earthquakes. It can also be becomes available in a practical form when underground heat is transferred by water that is heated as it passes through a subsurface region of hot rocks (a heat reservoir) that may be hundreds or thousands of feet deep. The water is usually naturally occurring groundwater that seeps down along fractures in the rock; less typically, the water is artificially introduced by being pumped down from the surface. The water is brought to the surface, as a liquid or steam, through holes drilled for the purpose.
By far the most abundant form of geothermal energy occurs at the relatively low temperatures of 80°to 180°centigrade. Water circulated through heat reservoirs in this temperature range is able to extract enough heat to warm residential, commercial, and industrial spaces. More than 20,000 apartments in France are now heated by warm underground water drawn from a heat reservoir in a geologic structure near Paris called the Paris Basin. Iceland sits on a volcanic structure known as the Mid-Atlantic Ridge. Reykjavik, the capital of Iceland, is entirely heated by geothermal energy derived from volcanic heat.
Geothermal reservoirs with temperatures above 180°centigrade are useful for generating electricity. They occur primarily in regions of recent volcanic activity as hot, dry rock; natural hot water; or natural steam. 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. By the late 1990s some 70 geothermal electric-generating plants were in operation in California, Utah, Nevada, and Hawaii, generating enough power to supply about a million people. Eighteen countries now generate electricity using geothermal heat.
Extracting heat from very hot, dry rocks present a more difficult problem: the rocks must be fractured to permit the circulation of water, and the water must be provided artificially. The rocks are fractured by water pumped down at very high pressures. Experiments are under way to develop technologies for exploiting this resource.
Like most other energy sources, geothermal energy presents some environmental problems. The surface of the ground can sink if hot groundwater is withdrawn without being replaced. In addition, water heated geothermally can contain salts and toxic materials dissolved from the hot rock. These waters present a disposal problem if they are not returned to the ground from which they were removed.
The contribution of geothermal energy to the world’s energy future is difficult to estimate. Geothermal energy is in a sense not renewable, because in most cases the heat would be drawn out of a reservoir much more rapidly than it would be replaced by the very slow geological processes by which heat flows through solid rock into a heat reservoir. However, in many places (for example, California, Hawaii, the Philippines, Japan ,Mexico, the rift valleys of Africa) the resource is potentially so large that its future will depend on the economics of production. At present, we can make efficient use of only naturally occurring hot water or steam deposits . Although the potential is enormous, it is likely that in the near future geothermal energy can make important local contributions only where the resource is close to the user and the economics are favorable, as they are in California, New Zealand, and Iceland. Geothermal energy probably will not make large-scale contributions to the world energy budget until well into the twenty-first century, if ever.
Earth’s internal heat, fueled by radioactivity, provides the energy for plate tectonics and continental drift, mountain building, and earthquakes. It can also be harnessed to drive electric generators and heat homes. Geothermal energy becomes available in a practical form when underground heat is transferred by water that is heated as it passes through a subsurface region of hot rocks (a heat reservoir) that may be hundreds or thousands of feet deep. ■ The water is usually naturally occurring groundwater that seeps down along fractures in the rock; less typically, the water is artificially introduced by being pumped down from the surface. ■The water is brought to the surface, as a liquid or steam, through holes drilled for the purpose. ■
By far the most abundant form of geothermal energy occurs at the relatively low temperatures of 80°to 180°centigrade.■ Water circulated through heat reservoirs in this temperature range is able to extract enough heat to warm residential, commercial, and industrial spaces. More than 20,000 apartments in France are now heated by warm underground water drawn from a heat reservoir in a geologic structure near Paris called the Paris Basin. Iceland sits on a volcanic structure known as the Mid-Atlantic Ridge. Reykjavik, the capital of Iceland, is entirely heated by geothermal energy derived from volcanic heat.
TPO21 托福阅读 Passage1 Geothermal Energy 题目
Question 1 of 14: According to the processes described in paragraph 1, what is the relationship between radioactivity and the steam produced by geothermal heat?
A. Geothermally heated steam is produced when water is exposed to radioactivity deep underground.
B. When water is introduced into holes drilled thousands of feet in the ground, it becomes radioactive and turns to steam.
C. Radioactivity heats Earth’s interior rock, which in turn can heat water to the point becomes steam.
D. When a reservoir of steam in subsurface rock is produced by radioactivity, it is said to be geothermally heated.
Question 2 of 14: The word “practical ”in the passage is closest in meaning to
Question 3 of 14: The word “abundant” in the passage is closest in meaning to
Question 4 of 14: According to paragraph 2, which of the following is true about heat reservoirs with a temperature in the range of 80°to 180°centigrade?
A. They are under international control.
B. They are more common than reservoirs that have a higher temperature.
C. Few of them produce enough heat to warm large industrial spaces.
D. They are used to generate electricity.
Question 5 of 14: According to paragraph 3, what is the connection between underground faults and naturally occurring steam?
A. Underground faults enable the heat from molten-rock material to escape upward to regions where it can heat surface water enough to produce steam.
B. Underground faults are created by steam that is produced in geothermal reservoirs deep inside Earth.
C. Underground faults create spaces in which natural steam is sometimes trapped.
D. Underground faults allow surface water to reach deep rocks that are hot enough to turn it into steam.
Question 6 of 14: In paragraph 3, why does the author mention that in the 1990s the Geysers were in its third decade of production?
A. To provide the historical context of the geothermal production of electricity in the United States
B. To imply that the Geysers was the first geothermal site to be put into production in California
C. To help explain the signs of decline shown by the Geysers
D. To explain why 70 new geothermal sites were put into electricity production in the late 1990s
Question 7 of 14: Which of the following can be inferred from paragraphs 2 and 3 about geothermal reservoirs?
A. Volcanic heat is associated only with geothermal reservoirs that have a temperature over 180°centigrade.
B. More countries produce power from geothermal reservoirs than use them for heating buildings.
C. Most geothermal reservoirs are suitable fro producing electricity.
D. A higher geothermal reservoir temperature is needed to generate electricity than is needed to heat homes.
Question 8 of 14: According to paragraph 4, extracting heat from very hot, dry rocks is difficult in part because
A. The underground rock must be fractured before heat can be removed from it.
B. The water above the rock is under very high pressure
C. The rock breaks apart when water is pumped into it
D. The water circulated through the rock must be much cooler than the rock itself
Question 9 of 14: The word “exploiting” in the passage is closest in meaning to
C making use of
D estimating the size of
Question10 of 14: How is the problem that the surface man sink related to the problem that water heated geothermally may contain toxic materials?
A. Both problems could be solved by returning groundwater that is removed from an underground heat reservoir back to the reservoir after heat is extracted from it .
B. The problem of sinking is more difficult to solve than is the problem of toxic materials.
C. Land at the surface sinks because the rock beneath the surface is weakened when salts and toxic materials are removed from it in the process of extracting geothermal energy.
D. Both problems are caused by the fact that the hot groundwater in a heat reservoir dissolves the rock, which weakens the rock and makes the water toxic with salt.
Question11 of 14: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
A. Heat flows through solid rock very slowly, so it takes a very long time for geological processes to produce a reservoir of geothermal energy.
B. Geothermal energy is not renewable because heat flows very slowly through solid rock into of our of a heat reservoir.
C. The heat quickly removed from a heat reservoir is replaced so slowly by geological processes that geothermal energy is not, practically speaking, renewable.
D. In most cases, heat travels into a heat reservoir so slowly that it is a much quicker process to remove the heat from a reservoir than to replace it.
Question 12 of 14: In paragraph 6, the author implies that in California, Hawaii, the Philippines, Japan, Mexico, and the rift valleys of Africa the potential size of the geothermal resource is so large that
A. It might be economically worth developing these sites even though geothermal energy is not renewable
B. These sites will be the first geothermal energy sites to be developed with new technology.
C. These sites are likely to make a large-scale contribution to the world energy budget in the twenty-first century
D. It does not matter whether they have naturally occurring deposits of hot water or steam.
Question13 of 14: Look at the four squares [■] that indicate where the following sentence could be added to the passage.
In either case, the heated water will usually be under. Where would the sentence best fit?
considerable pressure, and so may have a temperature that is well above its sea-level boiling point of 100°centigrade.
A. The water is usually naturally occurring groundwater that seeps down along fractures in the rock; less typically, the water is artificially introduced by being pumped down from the surface.
B. The water is brought to the surface, as a liquid or steam, through holes drilled for the purpose.
C. By far the most abundant form of geothermal energy occurs at the relatively low temperatures of 80°to 180°centigrade.
D. Water circulated through heat reservoirs in this temperature range is able to extract enough heat to warm residential, commercial, and industrial spaces.
Question14 of 14: Heat reservoirs in the form of hot rock far beneath Earth’s surface are a potential source of usable geothermal energy.
A. Heat reservoirs with a temperature from 80°to 180 °centigrade can be used, as in France and Iceland, to heat buildings.
B. Most heat reservoirs with a temperature above 180° Centigrade cannot be used for energy because they are usually too close to recent volcanic activity.
C. Experiments are under way to determine if geothermally heated waters could be used as a source of certain minerals that have been dissolved out of hot rocks deep within Earth.
D. A number of countries now use geothermal reservoirs that contain water or steam above 180°centigrade to generate electricity.
E. The sinking of land above heat reservoirs and water is pumped into a heat reservoir under high pressure.
F. A number of issues, including how to extract heat from reservoirs that do not have a natural supply of water , will significantly limit the use of geothermal energy for the foreseeable future.
Question 1 of 14
解析：问radioactivity和steam的关系，所以通过这两个关键词，分别定位至本段第一句和最后一句，第一句提到radioactivity提供了地球的内热，最后一句提到水变成蒸汽到达地表，水受热才能蒸汽，而这份热量是geothermal energy提供的，这就是二者的关系，所以答案是C。A的水暴露在radioactive underground时候steam产生文中未提及；B水变成radioactive原文未提及；D的radioactivity产生蒸汽不合文意。
Question 2 of 14
Question 3 of 14
Question 4 of 14
解析：以80到180度做关键词定位至第一句，提到最丰富的geothermal energy是在80到180度范围内的，所以同义替换是B的more common than higher temperature。A的international control原文未提及；C与本段第二句相反；D在本段没提，但下一段提到高于180度的可以用来发电，所以D与原文相反。
Question 5 of 14
解析：这是提问两者关系的题，找双关键词，定位至第三句，提到natural hot water和natural steam仅存在于那些地点，地表水通过fault或者fracture渗到地下，碰到……，所以可以看出答案是D。A说fault使heat跑上来，和原文的方向相反，原文是水跑下去；B说steam创造了fault不合文意；C的steam被trap原文未提及。
Question 6 of 14
Question 7 of 14
Question 8 of 14
解析：根据这个提问可以直接定位至第一句，提到从hot, dry rock抽热量是特别难的，必须先fracture rock，水也要人工引入，所以答案是A。D原文未提及，B和C原文确实有提到，但没有回答为什么难，也就是那种答非所问选项，所以也不正确。
Question 9 of 14
解析：exploit“开发，利用，剥削”，所以C的making use of正确。原文提到人们正在实践新的技术来怎么样这种资源，B“增加”很显然不正确；A“定位”和D“估计数量”都太初级了，而且现在的技术就可以定位和算储量，明显不对。
Question 10 of 14
Question 11 of 14
解析：原句的结构是geothermal energy是不renewable的，因为……，所以前面的结果即“geothermal energy是不renewable”的一定要有，A和D排除，；原句的原因中有一个比较，提到draw out比replace得快，C重现了这个比较，B没有，所以正确答案是C。
Question 12 of 14
解析：先读细节所在句，提到在这些资源如此充足的地方，资源的利用前景取决于economies of production，四个答案中只有A提到了开采是否划算的问题，所以答案是A。B和D原文未提及；C定位到最后一句，跟例子没什么关系。
Question 13 of 14
解析：这道题通过一个过渡点就可以确定正确答案，in either case说明正确插入点之前必须有两种情况，直接确定B，因为之前有usually和less typically两种情况。
Question 14 of 14
解析：A选项对应原文第二段，正确；注意不要因为“温度”和“国家”把 个选项当成细节，即使当成细节，也可以凭其他选项都不正确的排除法解决；B选项与原文第三段首句相反，不选；C选项对应原文第四段最后一句，但原文提到的是利用热能，不是矿物，所以这个选项不选；D选项对应原文第三段首句，正确；E选项对应第七段，原文并没有提到under high pressure，与原文不符，不选；F选项对应原文第六段的内容，正确。所以正确答案是ADF。