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题型:阅读理解 题类:真题 难易度:困难

2019年高考英语真题试卷(天津卷)

阅读理解

    How does an ecosystem(生态系统)work? What makes the populations of different species the way they are? Why are there so many flies and so few wolves? To find an answer, scientists have built mathematical models of food webs, noting who eats whom and how much each one eats.

    With such models, scientists have found out some key principles operating in food webs. Most food webs, for instance, consist of many weak links rather than a few strong ones. When a predator(掠食动物)always eats huge numbers of a single prey(猎物), the two species are strongly linked; when a predator lives on various species, they are weakly linked. Food webs may be dominated by many weak links because that arrangement is more stable over the long term. If a predator can eat several species, it can survive the extinction(灭绝)of one of them. And if a predator can move on to another species that is easier to find when a prey species becomes rare, the switch allows the original prey to recover. The weak links may thus keep species from driving one another to extinction.

Mathematical models have also revealed that food webs may be unstable, where small changes of top predators can lead to big effects throughout entire ecosystems. In the 1960s, scientists proposed that predators at the top of a food web had a surprising amount of control over the size of populations of other species—including species they did not directly attack.

    And unplanned human activities have proved the idea of top-down control by top predators to be true. In the ocean, we fished for top predators such as cod on an industrial scale, while on land, we killed off large predators such as wolves. These actions have greatly affected the ecological balance.

    Scientists have built an early-warning system based on mathematical models. Ideally, the system would tell us when to adapt human activities that are pushing an ecosystem toward a breakdown or would even allow us to pull an ecosystem back from the borderline. Prevention is key, scientists says because once ecosystems pass their tipping point(临界点), it is remarkably difficult for them to return.

(1)、What have scientists discovered with the help of mathematical models of food webs?
A、The living habits of species in food webs. B、The rules governing food webs of the ecosystems. C、The approaches to studying the species in the ecosystems. D、The differences between weak and strong links in food webs.
(2)、A strong link is found between two species when a predator______.
A、has a wide food choice B、can easily find new prey C、sticks to one prey species D、can quickly move to another place
(3)、What will happen if the populations of top predators in a food web greatly decline?
A、The prey species they directly attack will die out. B、The species they indirectly attack will turn into top predators. C、The living environment of other species will remain unchanged. D、The populations of other species will experience unexpected changes.
(4)、What conclusion can be drawn from the examples in Paragraph 4?
A、Uncontrolled human activities greatly upset ecosystems. B、Rapid economic development threatens animal habitats. C、Species of commercial value dominate other species. D、Industrial activities help keep food webs stable.
(5)、How does an early-warning system help us maintain the ecological balance?
A、By getting illegal practices under control. B、By stopping us from killing large predators. C、By bringing the broken-down ecosystems back to normal. D、By signaling the urgent need for taking preventive action.
举一反三
根据短文理解,选择正确答案。

    Obama, Lady Gaga and Steve Jobs—what do they have in common? They are, of course, all Americans. And according to a survey by social networking site baidu. com, they all best illustrate(举例说明) the word “cool”.

    But just what does it mean to say someone is “cool”? Most would answer that it is something to do with being independent-minded and not following the crowd.

    Yale University art professor Robert Farris Thompson says that the term “cool” goes back to 15th century West African philosophy. “Cool” relates to ideas of grace under pressure.

    “In Africa,” he writes, “coolness is a positive quality which combines calmness, silence, and life.”

    The modern idea of “cool” developed largely in the US in the period after World War II. “Post-war 'cool' was in part an expression of war-weariness (厌战情绪), . . . it went against the strict social rules of the time,” write sociologists Dick Pountain and David Robins in Cool Rules: Anatomy of an Attitude.

    But it was the American actor James Dean who became the symbol for “cool” in the hugely successful 1955 movie Rebel without a Cause. Dean plays a tough guy who disobeys his parents and the authorities. He always gets the girl, smokes cigarettes, wears a leather jacket and beats up bullies. In the movie, Dean showed what “cool” would mean to American young people for the next 60 years.

    Today the focus of “cool” has changed to athletics (体育运动) stars. Often in movies about schools, students gain popularity on the athletics field more than in the classroom. This can be seen quite clearly in movies like Varsity Blues and John Tucker Must Die.

    But many teenagers also think being smart is cool. Chess and other thinking games have been becoming more popular in schools.

    “Call it the Harry Potterization of America—a time when being smart is the new cool,” writes journalist Joe Sunnen.

阅读理解

    There is an old saying about volunteer work that goes like this: “ No one can do everything, but everyone can do something.”

    Today, many people volunteer their time and energy to help others. There are a lot of ways to meet other people's needs. For example, some volunteers provide help after a disaster. Others are happy to get dirty while repairing homes or planting trees or flowers in poor neighborhoods. Young people see suffering and loneliness around them and find ways to help. And history lovers help archeologists(考古学家) search for ancient objects to help deepen our knowledge of the past.

    Volunteers work in many areas around the world, including Haiti. More than four years have passed since a 7.0 earthquake shook the nation. The exact number of people who died may never be known. Thousands of survivors of the Haitian earthquakes still live in temporary shelters. Last year, former American President Jimmy Carter and his wife Rosalynn joined five hundred volunteers in the town of Leogane to build houses.

    Organizations do not have to be large to get volunteers. An activist group in Dharamsala, India is a good example, Jodie Underhill from England arrived in northern India several years ago. She planned to volunteer for an environmental project. She could almost not believe how much rubbish was ruining some of the area's most beautiful sights. Jodie Underhill learned about how to deal with the rubbish while taking part in other volunteer projects. But soon enough she formed her own group, Mountain Cleaners. Jodie Underhill says the work is very hard. But she praises the group's efforts as a wonderful experience. The young Englishwoman says the Indian media started calling her “Garbage Girl”. And she says she was pleased with the name.

    American teenagers also volunteer in many ways .

阅读理解

    Easter (复活节) is still a great day for worship (崇拜), randy in baskets and running around the yard finding eggs, but every year it gets quite a bit worse for bunnies (兔子).

    And no, not because the kids like to pull their ears. The culprit is climate change, and some researchers found that rising temperatures arc having harmful effects on at least five species of rabbit in the US.

    Take the Lower Keys March rabbit, for instance. An endangered species that lives in the Lower Florida Keys, this species of cottontail is a great swimmer—it lives on the islands!—but it is already severely affected by development and now by rising levels. According to the Center for Biological Diversity, an ocean level rise of only 0.6 meters will send these guys jumping to higher ground and a 0.9-meter rise would wipe out their habitat (栖息地) completely.

    The snowshoe hare, on the other hand, has a color issue. Most of these rabbits change their fur color from white in the wintertime to brown in the summer, each designed to give them better cover from  predators (捕食者). As the number of days with snow decreases all across the country, however, more and more bunnies arc being left in white fur during brown dirt days of both fall and spring, making them an easier mark for predators. Researchers know that the color change is controlled by the number of hours of sunlight, but whether the rabbit will be able to adapt quick enough to survive is a big question. The National Wildlife Federation has reported that hunters have noticed their numbers are already markedly down.

    American pikas or rock rabbits, a relative of rabbits and hares, might be the firs' of these species to go extinct due to climate change. About 7-8 inches long, pikas live high in the cool, damp mountains west of the Rocky Mountains. As global temperatures rise, they would naturally migrate (迁徙) to higher ground - but they already occupy (占据) the mountaintops. They can't go any higher. The National Wildlife Federation reports that they might not be able to stand the new temperatures as their habitat beats up.

    The volcano rabbit has the same problem. These rabbits live on the slopes of volcanoes in Mexico, and recent studies have shown that the lower range of their habitat has already shifted upward about 700 meters, but there are not suitable plants for them to move higher, so they are stuck in the middle. Scientists are concerned about their populations.

    Native to the US, pygmy rabbits weigh less than 1 pound and live in the American West. They are believed to be the smallest rabbits in the world. Their habitats have been destroyed by development. Several populations, such as the Columbia Basin pygmy, almost went extinct and were saved by zoo breeding programs. Pygmy rabbits also rely on winter cover by digging tunnels through the snow to escape predators, but lesser snowfall is leaving them exposed.

    All of this gives new meaning to dressing up in a giant bunny costume (服装) this Easter.

阅读理解

    Behind most of the bad things we do to our bodies as adults, eating more than we should is the idea we carry with us from childhood. On one hand, we assume that we are indestructible. On the other hand, we think that any damage we impose on ourselves can be undone when wβfinally clean up our act.

    If the evidence for how wrong the first idea is isn't apparent when you stand naked in front of the mirror, just wait. But what if you eat right and drop all your bad habits? Is there still time to repair the damage?

    To a surprising degree, the answer is yes. Over the past five years, scientists have collected a wealth of data about what happens when aging people with bad habits decide to turn their lives around.

    The heartening conclusion: the body has an amazing ability to heal itself, provided the damage is not too great.

    The effects of some bad habits-smoking, in particular-can haunt you for decades. But the damage from other habits can be largely healed.

    “Any time you improve your behavior and make lifestyle changes, they make a difference from that point on.” says Dr. Jeffey Koplan. “Maybe not right away. It's like slamming on the brakes. You do need a certain distance.”

But the distance can be remarkably short. Consider the recent announcements from the front lines of medical research: —A study concluded that women who consume as little as two servings of fish a week cut their risk of suffering a stroke to half that of women who eat less than one serving of fish a month. —The day you quit smoking, the carbon monoxide levels in your body drop dramatically. Within weeks, your blood becomes less sticky and your risk of dying from a heart attack starts to decline ... Adopting healthy habits won't cure all that bothers you, of course. But doctors believe that many chronic diseases-from high blood pressure to heart disease and even some cancers-can be warded off with a few sensible changes in lifestyle.

    Not sure where to start? Surprisingly, it doesn't matter, since one positive change usually leads to another. Make enough changes, and you'll discover you've adopted a new way of life.

Read the following passage. Choose the one that fits best according to the information given in the passage you have just read.

    A study involving 8, 500 teenagers from all social backgrounds found that most of them are ignorant when it comes to money. The findings, the first in a series of reports from NatWest that has started a five-year research project into teenagers and money, arc particularly worrying as this generation of young people is likely to be burdened with greater debts man any before.

    University tuition fees (学费) are currently capped at £3, 000 annually, but this will be reviewed next year and the Government is under enormous pressure to raise the ceiling.

    In the research, the teenagers were presented with die terms of four different loans but 76 per cent failed to identify the cheapest. The young people also predicted that they would be earning on average £ 31.000 by the age of 25, although the average salary for those aged 22 to 29 is just £ 17, 815. The teenagers expected to be in debt when they finished university or training, although half said that they assumed the debts would be less than £ 10.000. Average debts for graduates are £ 12, 363.

    Stephen Moir, head of community investment at the Royal Bank of Scotland Group which owns NatWest, said. "The more exposed young people are to financial issues, and the younger they become aware of them, the more likely they arc to become responsible, forward-planning adults who manage their finances confidently and effectively."

    Ministers are deeply concerned about the financial pressures on teenagers and young people because of student loans and rising housing costs. They have just introduced new lessons in how to manage debts. Nikki Fairweathcr, aged 15, from St Helens, said that she had benefited from lessons on personal finance, but admitted that she still had a lot to learn about money.

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