2017年3月25托福答案解析考试真题(2)
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
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。
2017年3月25日托福写作真题答案及解析
阅读：
给出了三个相关的理论。
1、Dating Error
因为土地沉降问题，所以soil layer对于时间上的证明是不准确的。
2、Trade
小麦并不是当地的农作物，而是有其他地方通过贸易手段到英国的。
3、British Farmers
当时英国还是以打猎为主，但是已经有部分的农民出现，只是没有大范文出现而已。
听力：
1、这种情况很少见，而且因为英国的土壤非常dense,这种transportation不太可能发生，而且在小麦的地层没有其他植物，所以不存在transportation.
2、那个时候只有南欧有小麦，在那个年代长距离贸易是非常困难的，所以不太可能。
3、小麦有reproduction process，所以一定会产生pollen，但是只发现了同时期其他植物的花粉，但是没有小麦的花粉，所以也不存在。
Sample Answer:
The reading lists three possible theories about the domesticated wheat in Britain. However, the lecturer contradicts all those claims perspectively.
First, about the dating error, which indicates that the wheat were actually much younger because of ocean wave transportation, the professor argues that the dirt in British is very dense, and there was no space for wheat to be downward and mixed up with older soil. Furthermore, other species in the upper soil have been discovered but they found nothing in the lower layers.
As to the possibility of trade, the professor also claims that it was too hard to be realized. At that time, wheat only occurred in south Europe and the agriculture had not been well-developed in north Europe, which means the boats at that age cannot meet the need of traveling for such a long distance. Thus, the hypothesis of trade in the reading passage cannot stand either.
Finally, the reading promotes an idea that there were a handful of farmers with certain skills to cultivate wheat. On the contrary, the professor starts with the theory that wheat have their own reproduction process, so they should release a characteristic pollen. In fact, no pollen were found in the layer of wheat, thus indicating that the wheat couldn't be cultivate artificially.
(213 words)
独立
Which one of the reason is most important in helping students to study in colleges and universities?
A、Having access to the university to tutors who can provide individual instruction for the students who have difficulty in study.
B、Having the help and encouragement from the family and friends.
C、Having an excellent teachers in high-school who can help the students before the university.
Use your OWN words to illustrate you point. Don’t use your memorized examples.
Sample Answer:
During the Renaissance, in many European countries, universities were only available to those who were born with silver spoon in their mouth and most of children had to work up to almost 19 hours a day in dingy factories. But now even the children in poverty can get access into universities and all kinds of support and help are aim to help students perform better in their college life. Given the choice, I would prefer the help and support from my families and friends.
We all believe that family members and friends are always in our position and know us better than tutors and high-school teachers. For those high-school students who are preparing for the university, parents give everything they have to provide their children with a better learning condition. Especially in Asian countries, the college entrance exam is a totally stiff competition that needs everyone to struggle through, during which the parents and friends act comprehensively as the tutors, the psychologists, the financial patrons even the servants for their daily life. Even though there is something wrong with those who are too dependent on parents and friends, the encouragement and supports from parents and friends can be adopted to some degree.
In comparison, helping from high-school teachers are not suitable at all. It is undeniable that there are huge difference between high schools and colleges, including learning skills, lifestyle and the way you get along with others. In terms of learning skills, the teacher-oriented schooling is popular in high school class, which means what the students need to do is just to sit in silence, listen carefully to teachers and take the practices in and after class. But this pattern is totally inapplicable in university. The professor leaves large space for class discussion and further team work outside the school, which is actually a better and flexible way for students to get in touch with new knowledge. I don't think a high-school teacher with rooted habit of class domination can bring the directions that meet the need of college education.
Some may claim that tutors are the better choice than parents and high-school teachers because they are professionals. The individual directions and pertinent advices are their specialties. Nevertheless, it is just suitable for kids. As an adult, being independent is the most important characteristic, or they will be at a loss in the occasion that no one helps them. The parents and friends also provide help but the difference is, they just provide help in materials, not directions in decision-making and project-planning. Thus, no matter what your age, independence in personality should not be overwhelmed by utilitarian goals.
All in all, there is nothing wrong with the help of high-school teachers and tutors. For the best possible learning, though, families and friends are the biggest help you can have. (470 words)
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