『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 21 Passage 1阅读练习：In paragraph 3, why does the author mention that in the 1990s The Geysers was in its third decade of production?真题题目及答案解析，TPO/Official 21 Passage 1阅读原文范文音频翻译

托福TPO/Official 21 Passage 1阅读原文In paragraph 3, why does the author mention that in the 1990s The Geysers was in its third decade of production?题目答案及解析-新东方托福官方网校手机版

地球内部的热量由放射性提供燃料，为板块构造和大陆漂移、造山和地震提供了能量。

Earth’s internal heat, fueled by radioactivity, provides the energy for plate tectonics and continental drift, mountain building, and earthquakes.

它还可以用来驱动发电机和取暖。

It can also be harnessed to drive electric generators and heat homes.

当水流经可能有几百英尺或几千英尺深的热岩石的地下区域（一种热库）时被加热，地下热量通过水传递，地热能就会以一种实用的形式存在。

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.

水通常是天然存在的地下水，沿着岩石的裂缝向下渗入；不太典型的情况是，水是通过从地表向下抽水的方式人工引入的。

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.

水以液体或蒸汽的形式通过专门钻出的孔被带到地表。

The water is brought to the surface, as a liquid or steam, through holes drilled for the purpose.

到目前为止，地热能最丰富的形式出现在相对较低的温度，即80摄氏度到180摄氏度。

By far the most abundant form of geothermal energy occurs at the relatively low temperatures of 80° to 180° centigrade.

在此温度范围内，通过热库循环的水能够提取足够的热量来为住宅、商业和工业空间取暖。

Water circulated through heat reservoirs in this temperature range is able to extract enough heat to warm residential, commercial, and industrial spaces.

目前，法国有超过2万套公寓通过温暖的地下水供暖，这些热水来自巴黎附近一个名为巴黎盆地的地质结构中的一个热库。

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.

冰岛坐落在被称为大西洋中脊的火山结构上。

Iceland sits on a volcanic structure known as the Mid-Atlantic Ridge.

冰岛首都雷克雅未克完全由火山热能产生的地热能供暖。

Reykjavik, the capital of Iceland, is entirely heated by geothermal energy derived from volcanic heat.

温度在180摄氏度以上的地热储可用于发电。

Geothermal reservoirs with temperatures above 180° centigrade are useful for generating electricity.

它们主要以干热岩石、天然热水或天然蒸汽的形式出现在近期火山活动的区域

They occur primarily in regions of recent volcanic activity as hot, dry rock; natural hot water; or natural steam.

后两种来源仅限于地表水通过地下断层或裂缝向下渗入到深层岩石的少数地区，这些深层岩石因最近熔岩物质活动而加热。

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.

世界上最大的天然蒸汽来源位于加利福尼亚州旧金山以北120公里处的间歇泉。

The world’s largest supply of natural steam occurs at The Geysers, 120 kilometers north of San Francisco, California.

在20世纪90年代，那里的发电量足以满足旧金山大约一半的（用电）需求。

In the 1990s enough electricity to meet about half the needs of San Francisco was being generated there.

该设施当时正处于生产的第三十个年头，并开始出现衰退的迹象，也许是由于过度开发。

This facility was then in its third decade of production and was beginning to show signs of decline, perhaps because of over development.

到20世纪90年代末，加利福尼亚州、犹他州、内华达州和夏威夷大约有70家地热发电厂投入运营，产生的电力足以满足约100万人的（用电）需求。

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.

现在有18个国家使用地热发电。

Eighteen countries now generate electricity using geothermal heat.

从非常热的、干燥的岩石中提取热量产生了一个更困难的问题：岩石必须有裂缝以允许水的循环，而且水必须是人工提供的。

Extracting heat from very hot, dry rocks presents 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.

开发利用这一资源的技术的实验正在进行中。

Experiments are under way to develop technologies for exploiting this resource.

与大多数其他能源一样，地热能也会产生一些环境问题。

Like most other energy sources, geothermal energy presents some environmental problems.

如果地下热水不经更换就被抽走，地面可能会下沉。

The surface of the ground can sink if hot groundwater is withdrawn without being replaced.

此外，通过地热方式加热的水可能含有从滚烫的岩石中溶解出来的盐和有毒物质。

In addition, water heated geothermally can contain salts and toxic materials dissolved from the hot rock.

这些水如果不返回它们被移出的地面，就会出现处置问题。

These waters present a disposal problem if they are not returned to the ground from which they were removed.

地热能对世界能源未来的贡献是难以估计的。

The contribution of geothermal energy to the world’s energy future is difficult to estimate.

从某种意义上说，地热能是不可再生的，因为在大多数情况下，热量从热库中被抽出的速度要比它被非常缓慢的地质过程所替换的速度快得多。在地质过程中，热量通过固体岩石流入热库。

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.

然而，在许多地方（例如，加利福尼亚州、夏威夷、菲律宾、日本、墨西哥、非洲裂谷），这种资源潜力巨大，其未来将取决于生产的经济情况。

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.

目前，我们只能有效地利用天然产生的热水或蒸汽沉淀物。

At present, we can make efficient use of only naturally occurring hot water or steam deposits.

尽管地热能的潜力巨大，但在不久的将来，地热能只有在离用户较近、经济效益较好的地方才能做出重要的贡献，正如在加利福尼亚州、新西兰和冰岛那样。

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.

如果说地热能会对世界能源预算做出大规模贡献的话，也许要等到二十一世纪才行。

Geothermal energy probably will not make large-scale contributions to the world energy budget until well into the twenty-first century, if ever.

According to the processes described in paragraph 1, what is the relationship between radioactivity and the steam produced by geothermal heat?

The word “practical” in the passage is closest in meaning to

The word “abundant” in the passage is closest in meaning to

According to paragraph 2, which of the following is true about heat reservoirs with a temperature in the range of 80° to 180° centigrade?

According to paragraph 3, what is the connection between underground faults and naturally occurring steam?

In paragraph 3, why does the author mention that in the 1990s The Geysers was in its third decade of production?

Which of the following can be inferred from paragraphs 2 and 3 about geothermal reservoirs?

According to paragraph 4, extracting heat from very hot, dry rocks is difficult in part because

The word “exploiting” in the passage is closest in meaning to

How is the problem that the surface may sink related to the problem that water heated geothermally may contain toxic materials?

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.

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

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 considerable pressure, and so may have a temperature that is well above its sea-level boiling point of 100° centigrade.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.

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 sentences 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.

Geothermal Energy 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. 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 presents 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.