下面是智课网针对最新一次托福考试,给大家特别整理了真题回顾的解析,本文的内容是2017年3月25日托福阅读真题答案及解析,包括原文的再现以及词汇的整理,希望给大家备考提供更多帮助!

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  Passage One

  学科分类:农业类

  题目:Soil Fertilization

  内容回忆: 真题Soil Fertilization

  Fertilizers partially restore plant nutrients lost by erosion, crop harvesting, and leaching. Farmers can use either organic fertilizer from plant and animal materials or commercial inorganic fertilizer produced from various minerals. Three basic types of organic fertilizer are animal manure, green manure, and compost. Animal manure includes the waste matter of cattle, horses, poultry, and other farm animals. It improves soil structure, adds organic nitrogen, and stimulates beneficial soil bacteria and fungi.

  Despite its effectiveness, the use of animal manure in the United States has decreased. There are three reasons for this: the replacement of most mixed animal-raising and crop-farming operations with separate operations for growing crops and raising animals, the high costs of transporting animal manure from feedlots near urban areas to distant rural crop-growing areas, and the replacement of horses and other draft animals that added manure to the soil with tractors and other motorized farm machinery.

  Green manure is fresh or growing green vegetation plowed into the soil to increase the organic matter and humus (degraded organic matter) available to the next crop. Compost is a sweet-smelling, dark-brown, humuslike material that is rich in organic matter and soil nutrients. It is produced when microorganisms in soil (mostly fungi and aerobic bacteria) break down organic matter such as leaves, food wastes, paper, and wood in the presence of oxygen. Compost is a rich natural fertilizer and soil conditioner that aerates soil, improves its ability to retain water and nutrients, helps prevent erosion, and prevents nutrients from being wasted by being dumped in landfills. Compost is produced by piling up alternating layers of nitrogen-rich wastes (such as grass clippings, weeds, animal manure, and vegetable kitchen scraps), carbon-rich plant wastes (dead leaves, hay, straw, sawdust), and topsoil. Compost provides a home for microorganisms that help decompose plant and manure layers and reduces the amount of plant wastes taken to landfills and incinerators.

  Another form of organic fertilizer is the spores of mushrooms, puffballs, and truffles. Rapidly growing and spreading mycorrhizae fungi in the spores attach to plant roots and help them take in moisture and nutrients from the soil. Unlike typical fertilizers that must be applied every few weeks, one application of mushroom fungi lasts all year and costs just pennies per plant. The fungi also produce a bigger root system, which makes plants more disease resistant.

  Corn, tobacco, and cotton can deplete the topsoil of nutrients, especially nitrogen, if planted on the same land several years in a row. One way to reduce such losses is crop rotation. Farmers plant areas or strips with nutrient-depleting crops one year. In the next year they plant the same areas with legumes, whose root nodules add nitrogen to the soil. In addition to helping restore soil nutrients, this method reduces erosion by keeping the soil covered with vegetation and helps reduce crop losses to insects by presenting them with a changing target.

  Today, many farmers rely on commercial inorganic fertilizers containing nitrogen (as ammonium ions, nitrate ions, or urea), phosphorus (as phosphate ions), and potassium (as potassium ions). Inorganic commercial fertilizers are easily transported, stored, and applied. Worldwide, their use increased about tenfold between 1950 and 1989 but declined by 12% between 1990 and 1999. Today, the additional food they help produce feeds one of every three people in the world, without them, world food output, would drop an estimated 40%.

  Commercial inorganic fertilizers have some disadvantages, however. These include (1) not adding humus to the soil, (2) reducing the soil’s content of organic matter and thus its ability to hold water (unless animal manure and green manure are also added to the soil), (3) lowering the oxygen content of soil and keeping fertilizer from being taken up as efficiently, (4) typically supplying only two or three of the twenty or so nutrients needed by plants, and (5) releasing nitrous oxide, a greenhouse gas that can enhance global warming. The widespread use of commercial inorganic fertilizers, especially on sloped land near streams and lakes, also causes water pollution as nitrate and phosphate fertilizer nutrients are washed into nearby bodies of water. The resulting plant nutrient enrichment causes algae blooms that use up oxygen dissolved in the water, thereby killing fish.

  Paragraph 1

  Fertilizers partially restore plant nutrients lost by erosion, crop harvesting, and leaching. Farmers can use either organic fertilizer from plant and animal materials or commercial inorganic fertilizer produced from various minerals. Three basic types of organic fertilizer are animal manure, green manure, and compost. Animal manure includes the waste matter of cattle, horses, poultry, and other farm animals. It improves soil structure, adds organic nitrogen, and stimulates beneficial soil bacteria and fungi.

  本文是2017年3月25日托福阅读真题答案及解析。

  1、The word "beneficial" in the passage is closest in meaning to

  necessary

  helpful

  several

  hidden

  Paragraph 2

  Despite its effectiveness, the use of animal manure in the United States has decreased. There are three reasons for this: the replacement of most mixed animal-raising and crop-farming operations with separate operations for growing crops and raising animals, the high costs of transporting animal manure from feedlots near urban areas to distant rural crop-growing areas, and the replacement of horses and other draft animals that added manure to the soil with tractors and other motorized farm machinery.

  2、According to paragraph 2, all of the following contributed to the decrease in the use of animal manure in the United States EXCEPT

  changes in crop-farming and animal-raising operations

  high transportation costs

  the movement or large numbers of feedlots to distant rural areas

  the introduction of motorized farm machinery

  Paragraph 3

  Green manure is fresh or growing green vegetation plowed into the soil to increase the organic matter and humus (degraded organic matter) available to the next crop. Compost is a sweet-smelling, dark-brown, humuslike material that is rich in organic matter and soil nutrients. It is produced when microorganisms in soil (mostly fungi and aerobic bacteria) break down organic matter such as leaves, food wastes, paper, and wood in the presence of oxygen. Compost is a rich natural fertilizer and soil conditioner that aerates soil, improves its ability to retain water and nutrients, helps prevent erosion, and prevents nutrients from being wasted by being dumped in landfills. Compost is produced by piling up alternating layers of nitrogen-rich wastes (such as grass clippings, weeds, animal manure, and vegetable kitchen scraps), carbon-rich plant wastes (dead leaves, hay, straw, sawdust), and topsoil. Compost provides a home for microorganisms that help decompose plant and manure layers and reduces the amount of plant wastes taken to landfills and incinerators.

  3、According to paragraph 3, what is one advantage of using compost in raising crops?

  It makes the soil easier to plow in preparation for planting.

  Water and nutrients stay in the soil and enable plant growth.

  The damage to soil from microorganisms is reduced.

  Excess oxygen is removed from the soil.

  4、According to paragraph 3, one important physical effect of compost is that it

  adds an oxygen-rich layer to the layers rich in nitrogen and carbon

  decreases the quantity of plant material that needs to be discarded

  helps keep the same amount of moisture in each layer of soil

  reduces the amount of fungi and aerobic bacteria in the pile

  Paragraph 4

  Another form of organic fertilizer is the spores of mushrooms, puffballs, and truffles.

  Rapidly growing and spreading mycorrhizae fungi in the spores attach to plant roots and help them take in moisture and nutrients from the soil. Unlike typical fertilizers that must be applied every few weeks, one application of mushroom fungi lasts all year and costs just pennies per plant. The fungi also produce a bigger root system, which makes plants more disease resistant.

  5、According to paragraph 4, each of the following is an advantage of using mushroom spores as fertilizer EXCEPT:

  The cost of using mushroom spores is relatively low.

  A single application of mushroom spores is enough for a whole year.

  Mushroom fungi are nutrients that plants can take in easily.

  Mushroom fungi help protect plants from disease.

  Paragraph 5

  Corn, tobacco, and cotton can deplete the topsoil of nutrients, especially nitrogen, if planted on the same land several years in a row. One way to reduce such losses is crop rotation. Farmers plant areas or strips with nutrient-depleting crops one year. In the next year they plant the same areas with legumes, whose root nodules add nitrogen to the soil. In addition to helping restore soil nutrients, this method reduces erosion by keeping the soil covered with vegetation and helps reduce crop losses to insects by presenting them with a changing target.

  6、What is the ¯target‖ referred to in the passage?

  Crop losses that are caused by insects

  The crop being grown at any given time

  The areas that are planted with legumes

  The various insects that cause crop losses

  7、According to paragraph 5, one of the main reasons for using legumes in crop rotation is that legumes

  have no serious insect pests

  cover the soil more completely than any other crop does

  build up the nitrogen content of the soil

  are very easy to plant in strips

  Paragraph 6

  Today, many farmers rely on commercial inorganic fertilizers containing nitrogen (as ammonium ions, nitrate ions, or urea), phosphorus (as phosphate ions), and potassium (as potassium ions). Inorganic commercial fertilizers are easily transported, stored, and applied. Worldwide, their use increased about tenfold between 1950 and 1989 but declined by 12% between 1990 and 1999. Today, the additional food they help produce feeds one of every three people in the world, without them, world food output, would drop an estimated 40%.

  8、The word "rely" in the passage is closest in meaning to

  save

  depend

  pile

  waste money

  9、According to paragraph 6, what is true about the quantities of commercial inorganic fertilizers used globally?

  They are likely to drop by about 40% in the next ten years.

  They have increased at a steady rate since 1950.

  They increased during the 1990s, but at a slower rate than over the previous 40 years.

  They dropped during the 1990s after having risen sharply over the previous 40 years.

  Paragraph 7

  Commercial inorganic fertilizers have some disadvantages, however. These include (1) not adding humus to the soil, (2) reducing the soil’s content of organic matter and thus its ability to hold water (unless animal manure and green manure are also added to the soil), (3) lowering the oxygen content of soil and keeping fertilizer from being taken up as efficiently, (4) typically supplying only two or three of the twenty or so nutrients needed by plants, and (5) releasing nitrous oxide, a greenhouse gas that can enhance global warming. The widespread use of commercial inorganic fertilizers, especially on sloped land near streams and lakes, also causes water pollution as nitrate and phosphate fertilizer nutrients are washed into nearby bodies of water. The resulting plant nutrient enrichment causes algae blooms that use up oxygen dissolved in the water, thereby killing fish.

  10、How is paragraph 7 related to paragraph 6?

  Paragraph 7 presents the drawbacks of a practice that paragraph 6 presents as an advantage.

  Paragraph 7 argues that the viewpoint presented in paragraph 6 is based on several factual errors.

  Paragraph 7 provides supporting evidence for some of the claims made in paragraph 6.

  Paragraph 7 contrasts recently developed practices with the more traditional, established ones discussed in paragraph 6.

  11、The phrase "twenty or so" in the passage is closest in meaning to

  not quite twenty

  roughly twenty

  no more than twenty

  a total of twenty

  12、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.

  The main cause of water pollution is the widespread use of commercial inorganic fertilizers on sloped land near streams and lakes.

  In addition, the widespread use of commercial inorganic fertilizers causes water pollution when nitrates and phosphates are washed into streams and lakes.

  Also, the widespread commercial production of inorganic fertilizers has caused water pollution in bodies of water such as streams and lakes.

  The most commonly used commercial inorganic fertilizers are nitrate and phosphate fertilizers, which cause water pollution if they enter streams or lakes.

  Paragraph 1

  Fertilizers partially restore plant nutrients lost by erosion, crop harvesting, and leaching. ■ Farmers can use either organic fertilizer from plant and animal materials or commercial inorganic fertilizer produced from various minerals. ■

  Three basic types of organic fertilizer are animal manure, green manure, and compost. ■ Animal manure includes the waste matter of cattle, horses, poultry, and other farm animals. ■ It improves soil structure, adds organic nitrogen, and stimulates beneficial soil bacteria and fungi.

  13、Look at the four squares [■] that indicate where the following sentence can be added to the passage.

  Thus, they help keep farmland productive over the long term.

  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.

  SHAPE \* MERGEFORMAT

  Both organic and inorganic fertilizers are used to keep croplands productive.

  Answer Choices

  Animal manures are effective organic fertilizers, but their use in the United States has decreased because of changes in modern farming.

  Many economically important crops, including corn, tobacco, and cotton, can only be grown in the same fields year after year if large amounts of inorganic fertilizers are added to the soil.

  Since 1950, farmers worldwide have begun to replace organic fertilizers with inorganic commercial ones, because the latter helps soil to retain oxygen.

  Compost, a humuslike material that is rich in organic material, is often used together with green manure, since the combination of the two helps to prevent soil erosion.

  correctly, all have positive impacts on growing conditions for crops that go beyond simply providing nutrients.

  Commercial inorganic fertilizers play a key role in feeding the world’s population, but they can also cause serious environmental damage.

  答案:BCBBC,BCBDA,BBA,AEF

  本文的内容是2017年3月25日托福阅读真题答案及解析。

  Passage Two

  学科分类:地质类

  题目:Earthquake prediction

  内容回忆:

  地震的预测有长期预测和短期预测,长期预测主要是靠地壳运动的变化来推测地震发生的地点和时间。短期预测主要是通过化学元素物质的密度以及在土地、水流中的沉降变化来判断。

  开头段两行比较简短,介绍了地震预测的大致情况。

  第二段介绍了长期预测的情况,通过地壳运动、洋流,依据大陆板块漂移学说来预测将来的地震发生情况。

  第三段介绍了短期预测的方法,通过一种化学物质的变化来反应地质运动。

  第四段详细解释了该种物质在水流里的体现。

  第五段探究了地震预测对于人类发展的意义。

  词汇题:

  1. specified

  2. focused

  3. imminent

  4. retirement

  Passage Three

  学科分类:生物类

  题目:Butterfly wings pattern and predator defension

  内容回忆:

  蝴蝶的翅膀可以用来帮助它们躲避捕食者的捕猎。主要有三种形式:伪装色,警告色以及恐吓色。

  第一段引出了蝴蝶翅膀的纹路有三种形式来影响捕食者,特别是通过视觉来捕猎的动物。

  第二段详细介绍了伪装色的作用,举例说明了蝴蝶翅膀会伪装成周围树林、水流等颜色。

  第三段详细介绍了警告色的使用,有些蝴蝶翅膀的样式会告诉捕食者自己的不可食用性。

  第四段详细介绍了恐吓色的作用,大多以眼睛的样式展现,告诉捕食者该物种的体型等,产生错觉。

  第五段进一步阐述了恐吓色的应用。

  词汇题:

  1. virtually

  2. startled

  3. disturb

  4. rudimentary

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