选择知识点

阅读下列短文，从每题所给的四个选项（A、B、C和D）中选出最佳选项。
You might think that “global warming” means nothing more than a rise in the world's temperature. But rising sea levels caused by it have resulted in the first evacuation (撤离) of an island nation, the citizens of Tuvalu will have to leave their homeland.
During the 20th century, sea level rose 8~12 inches. As a result, Tuvalu has experienced lowland flooding of salt water that has polluted the country's drinking water.
Paani Laupepa, a Tuvaluan government official, reported to the Earth Policy Institute that the nation suffered an unusually high number of fierce storms in the past ten years. Many scientists connect higher surface water temperatures resulting from global warming to greater and more damaging storms.
Laupepa expressed dissatisfaction with the United States for refusing to sign the Kyoto Protocol, an international agreement calling for industrialized nations to reduce their greenhouse gas emissions (排放), which are a main cause of global warming. “By refusing to sign the agreement, the US has effectively taken away the freedom of future generations of Tuvaluans to live where their forefathers have lived for thousands of years.” Laupepa told the BBC.
Tuvalu has asked Australia and New Zealand to allow the gradual move of its people to both countries.
Tuvalu is not the only country that is vulnerable (易受影响的) to rising sea levels. Maumoon Gayoon, president of the Maldives, told the United Nations that global warming has made his country of 311,000 an “endangered nation”.
（1）What is the text mainly about?
A.Rapid changes in earth's temperature. 
B.Bad effects of global warming.
C.A country moving to a new place.
D.Reasons for lowland flooding.
（2）According to scientists, what is the direct cause of more and fiercer storms?
A.Greenhouse gas emissions in industrialized nations.
B.Higher surface water temperatures of the sea.
C.Continuous global warming.
D.Rising sea levels.
（3）Laupepa was not satisfied with the United States because it did not ________.
A.agree to reduce its greenhouse gas emissions
B.believe the problems facing Tuvalu were real
C.allow Tuvaluans to move to the US
D.sign an agreement with Tuvalu
（4）The country whose situation is similar to that of Tuvalu is ________.
A.Australia
B.New Zealand
C.the Maldives
D.the United States

阅读理解。

Even if trees cannot walk, they are still on the move.
In parts of the Arctic, entire forests are moving northward. Across the Arctic, temperatures are rising faster than anywhere else in the world. As that happens, the tree line that marks where forests stop and the treeless tundra(冻土地带) starts has been shifting northward. Trees growing along the tree line must protect themselves from the cold wind. To do this, plants tend to grow horizontal(水平的) branches low to the ground. The energy it takes for trees to grow this way means they don't have enough energy to make seeds.
But as Earth's climate has been warming, trees no longer have to just grow horizontally. Many can instead grow up toward the sky. This takes less energy. And with all the leftover energy. these trees have started producing more seeds. This happens especially in places where the white spruce(白云杉) grows.
White spruce, which is a North American tree, is quite able to produce a lot of seeds, which can move long distances in the wind. When wind-blown seeds end up on the tundra beyond the tree line, they eventually can sprout(发芽) new trees. This explains how a forest can move. Of course, the process would work only if the tundra were warm enough. But in recent years, the whole planet has been warming.
New trees will provide shelters for some snow, keeping the sun's rays from making the white surface disappear. Instead, the trees absorb the sun's heat. This warms the surrounding air. The extra warmth encourages even more trees to produce seeds. That further boosts a forest's ability to expand. In addition, more trees will trap more snow, preventing much of it from being blown away. Snow can trap heat in the soil below, which encourages trees to grow. The recent rise of temperature has helped more trees grow. The recent rise of temperatures has helped more trees grow past the tree line. People worry about impacts on the animals that depend on frozen conditions for food and shelter.
（1）What is the main cause of the trees in the Arctic moving northward?
A.The rising temperature.
B.The shrinking of northern tundra.
C.The fierce and cold wind.
D.The abundant resources in the north.
（2）What does the underlined word“this”in Paragraph 2 mean?
A.To produce more seeds.
B.To move northward.
C.To respond to the climate change.
D.To protect themselves from the cold wind.
（3）What can be inferred from the last paragraph?
A.New trees can trap the snow, which may make the soil colder.
B.The trapped snow prevents new trees from producing more seeds.
C.New trees can make the surrounding air warmer.
D.New trees can bring more food and shelter for local animals.
（4）The passage is most probably taken from _______.
A.a health report
B.a science report
C.a fashion magazine
D.a children's magazine

阅读下列短文，从每题所给的四个选项 （A 、B 、C 和 D ）中，选出最佳选项。

The human brain contains 10 thousand million cells and each of these may have a thousand connections. Such enormous numbers used to discourage us and cause us to dismiss the possibility of making a machine with human-like ability, but now that we have grown used to moving forward at such a pace we can be less sure. Quite soon, in only 10 or 20 years perhaps, we will be able to assemble a machine as complex as the human brain, and if we can we will. It may then take us a long time to render it intelligent by loading in the right software (软件)or by altering the architecture but that too will happen.
I think it certain that in decades, not centuries, machines of silicon (硅) will arise first to compete and then do better than their human ancestors. Once they do better than us they will be capable of their own design. In a real sense they will be able to reproduce themselves. Silicon will have ended carbon's long control. And we will no longer be able to claim ourselves to be the finest intelligence in the known universe.
As the intelligence of robots increases to match that of humans and as their cost declines through economies of scale we may use them to improve environments. Thus, deserts may bloom and the ocean beds be mined. Further ahead, by a combination of the great wealth this new age will bring and the technology it will provide, the construction of a vast, man-created world in space, home to thousands or millions of people, will be within our power.
（1）In what way can we make a machine intelligent?
A.By making it work in such environments as deserts, oceans or space.
B.By working hard for 10 or 20 years.
C.By either properly programming it or changing its structure.
D.By reproducing it.
（2）What does the writer think about machines with human-like ability?
A.He believes they will be useful to human beings.
B.He believes that they will control us in the future.
C.He is not quite sure in what way they may influence us.
D.He doesn't consider the construction of such machines possible.
（3）The word “carbon” (Line 4, Para.2) stands for _________.
A.intelligent robots
B.a chemical element
C.an organic substance
D.human beings
（4）It can be inferred from the passage that _______.
A.after connections with phones, robots will be able to have self-reproduction
B.people have come to realize the possibility of making a machine with human-like ability
C.once we make a machine as complex as the human brain, it will have intelligence
D.robots will have control of the vast, man-made world in space

阅读理解
Global warming threatens to hold back human progress, and make unachievable all UN targets to reduce poverty, according to some of the world's leading international and development groups.
In a report published today, Oxfam, Greenpeace and other groups say rich governments must immediately address climate change to avoid even “unbearable levels” of worldwide poverty.
“Food production, water supplies, public health and people's livelihoods are already being damaged and weakened,” the report says. “There is no approach possible. The world must meet its commitments to achieve poverty reduction and also deal with climate change, which are closely linked.”
The report, which draws on UN predictions of the effects of climate change in poor countries over the next 50 years, says poor countries will experience more flooding, declining food production, more disease and the extinction of entire eco-systems on which many of the world's poorest people depend.
“Climate change needs to be addressed now. The poor will bear the great consequence of it. The frontline experience of many of us working in international development indicates that communities are having to fight more extreme weather conditions.”
Climate change will cause great damage to agriculture and water supplies and will increase diseases. “By 2025 the number of the world's population living in countries of significant water stress will almost double, to 6 billion people. Tropical (热带的) and sub-tropical areas will be hardest hit — those countries already suffering from food shortage”.
Poor countries mostly do not need hi-tech solutions, but would most benefit from education, research and being shown how to farm better. The report says unchecked global warming, more than wars or political upheaval (政变), will displace millions of people and unsettle many countries.
（1）Which of the following is NOT related to global warming according to the passage?
A.Fitness
B.Food production
C.Water supplies
D.Farming
（2）What does the underlined word “address” in Paragraph 2 mean?
A.settle
B.speak
C.occupy
D.write an address
（3）Where may the passage be taken from?
A.A diary
B.A novel
C.A magazine
D.A news report
（4）Which of the following is the main topic discussed in the passage?
A.Global warming: causing damage to agriculture
B.Global warming: causing damage to water supplies
C.Global warming: a bigger threat to humans
D.Global warming: a bigger threat to the poor

阅读理解
Good afternoon, and welcome to England. We hope that your visit here will be a pleasant one. Today, I would like to draw your attention to a few of our laws.
The first one is about drinking. Now, you may not buy alcohol in this country if you are under 18 years of age, nor may your friends buy it for you.
Secondly, noise, Enjoy yourselves by all means, but please don't make unnecessary noise, particularly at night. We ask you to respect other people who may wish to be quiet.
Thirdly, crossing the road. Be careful. The traffic moves on the left side of the road in this country. Use pedestrian crossings and do not take any risk when crossing the road.
My next point is about litter（throwing away wasted material in a public place）. It is an offence to drop litter in the street. When you have something to throw away, please put it in your pocket and take it home, or put it in a litter bin.
Finally, as regards smoking, it is against the law to buy cigarettes or tobacco if you are under 16 years of age.
I'd like to finish by saying that if you requires any sort of help or assistance, you should get in touch with your local police station, who will be pleased to help you.
Now, are there any questions?
（1）The main purpose of this speech would be to ________.
A.prepare people for international travel
B.declare the laws of different countries
C.give advice to travelers to the county
D.inform people of the punishment for breaking laws
（2）From the speech we learn that ________.
A.in this country, if you are under 18 years of age, you may not buy alcohol, but your friend can buy it for you.
B.you may not buy cigarettes or tobacco unless you are above 16 years of age
C.because the traffic moves on the right side of the road, you must use pedestrian crossings when crossing the road.
D.you can't make noise except at night.
（3）Who do you think is most likely to make the speech?
A.A policeman
B.A lawmaker
C.A teacher
D.A lawyer

阅读理解Yellowstone Weather
Yellowstone National Park is at high altitude. Most of the park is above 7,500 feet (2,275 meters).
Yellowstone's weather is unpredictable. In summer, it may be warm and sunny with temperatures in the high 70s. At night in any given month, the temperature may drop close to freezing. So it is best to come prepared for cold evenings and mornings, especially if you are camping or hiking. When you leave your campsite, please leave it prepared for possible thundershowers and wind.
A sunny warm day may become fiercely stormy with wind, rain, sleet and sometimes snow. Without enough clothing, and easy day hike or boat trip can turn into a battle for survival.

（1）The author writes this passage most probably for those who plan to ______ in Yellowstone National Park.
A.do research work
B.take a business trip
C.have sports games
D.spend their holidays or take a tour
（2）Which of the following best describes Yellowstone's weather?
A.Yellowstone's weather is generally changeable and it snows most of the year.
B.It's neither too hot in summer nor too cold in winter.
C.Weather in fall is pleasant and temperatures never fall below freezing.
D.It's pretty warm in the day and very cool at night throughout the year.
（3）If you are planning to spend your holidays in Yellowstone National Park in summer, what should you take with you?
A.Just some light clothing such as T-shirts or skirts.
B.Just some warm clothing such as sweaters and coats.
C.Both light clothing and warm clothing.
D.Either light clothing or warm clothing.
（4）What does the underlined word “readings” refer to?
A.literature works
B.scientific data
C.announcements
D.figures.

阅读理解
Nuclear power's danger to health, safety, and even life itself can be summed up in one word: radiation.
Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can't be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can't detect them, sense them, without a radio receiver. Similarly, we can't sense radioactivity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things.
At very high levels, radiation can kill an animal or human being immediately by killing masses of cells in vital organs. But even the lowest levels can do serious damage. There is no levels of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be serious. This is the case when only a few cells are hit, and if they are killed immediately. Your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They can grow into cancer. Sometimes this does not show up for many years.
This is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can be irradiated(辐射)and feel fine, then die for cancer five, ten, or twenty years later as a result. Or a child can be born weak as a result of radiation absorbed by its grandparents.
Radiation can hurt us. We must know the truth.
（1）Which of the following statements is true?
A.Nuclear radiation is just like common radio waves.
B.Nuclear radiation can cause cancer to human beings.
C.Nuclear radiation can be detected by human senses.
D.Nuclear radiation can be safe to human beings if its level is low.
（2）How can nuclear radiation kill an animal?
A.By damaging its heart.
B.By killing a few cells.
C.By hitting any place in its body.
D.By killing many cells in important organs.
（3）If a human being is hit by nuclear radiation, he may __________.
A.die of cancer after many years
B.die immediately
C.have a child who may be born weak
D.all of the above

阅读理解
2017 was an influential year for artificial intelligence (人工智能), not just in terms of the advancement of the technology itself, but also for the development of our understanding of AI's impact on our society.

When we talk about AI, often we focus on the belief that it is going to take away certain types of jobs. However, we often ignore the fact that this technology will also slowly spread into most of our lives.
Thanks to the development of AI, we are on the highway of IA, (human) intelligence augmentation (增强). Despite the great steps we've made in AI development and will continue to make in 2018, we are still years away from AI fully replacing human jobs. However, we are much closer to seeing the impact of AI spread into almost every job and the growth in human intelligence.
Take a doctor for example: AI will soon be able to detect and diagnose common diseases more quickly and accurately than humans. Now, doctors can spend more of their time explaining the possible diagnoses, communicating with patients and developing unique, reliable treatment plans that are most effective for each specific patient.
However, AI is so powerful and its adoption will only accelerate as it begins to help our work and allow us to focus on the parts of our job that are most important. But part of why AI is so attractive is also why it's so dangerous. That is, that same power allows AI that are making incorrect decisions to do so with greater speed and impact than humans have ever had.
This is why, as AI becomes more useful in 2018, it will also become more closely examined. 2018 will be the year when companies purchasing AI products don't just ask about the power of AI—they will make sure that it is tested carefully in advance, minimizing their potential unexpected impact.
（1）What does the author suggest in the first two paragraphs?
A.Many jobs should be replaced by AI in the future.
B.People should think more about the impact of AI.
C.AI is too abstract for ordinary people to understand.
D.People care little about the development of AI.
（2）The author takes the example of “the doctor” to explain that       .
A.AI always makes right decisions
B.doctors will lose their jobs very soon
C.human intelligence grows with AI
D.humans are no better than AI in medicine
（3）What will be the focus about AI in 2018 according to the author's prediction?
A.The safety of AI.
B.The possibility of replacing humans.
C.Cost reduction.
D.Power augmentation.
（4）What is the author's attitude towards AI?
A.Indifferent.
B.Negative.
C.Doubtful.
D.Objective.

阅读理解

There are lots of insects that farmers hate. But there also are some they like. They protect crops against damage from other insects. A good example is the lady beetle, which is also known as the ladybug(瓢虫)．
Lady beetles are a natural control for aphids(蚜虫). Lady beetles are red, orange or black. They often have black spots, though some have light colored spots. Different kinds of lady beetles have different numbers of spots. There are lady beetles with four, five, seven and fourteen spots.
Many of the well-known kinds of lady beetles come from Asia or Europe. They now are common throughout the United States.
American scientists imported one kind of lady beetle, the multicolored Asian lady beetle, as early as 1916. They released them as an attempt to control some kinds of insects. Over the years, the beetle has become established, possibly helped by some that arrived with imported plants on ships.
Experts say over 450 kinds of lady beetles are found in North America. Some are native to the area. Others have been brought from other places. Almost all are helpful to farmers.
The Asian lady beetles now in the United States probably came from Japan. The Asian lady beetle eats aphids that damage crops like soybeans, fruits and berries.
In the southern United States, Asian lady beetles have reduced the need for farmers to use reskilling poisons on pecan trees. This popular tree nut suffers from aphids and other pests that the lady beetles eat.
But some people say the Asian lady beetle has itself become a pest. They worry that the lady beetles may eat their late autumn fruit crops.
Experts say Asian lady beetles may appear in large numbers in some years. But they say the insects are too helpful to be considered as pests.
（1）What do ladybugs look like?
A.All kinds of ladybugs are of the same color.
B.Most of them are red, orange or black.
C.They each have the same number of spots on them.
D.Most of them have fourteen spots.
（2）Asian ladybugs have been in the United States for______.
A.nine decades
B.hundreds of years
C.half a century
D.a century
（3）According to the passage the following statements are supported EXCEPT________.
A.there are more than 450 kinds of ladybugs in North America, including native ones
B.only some imported ladybugs are helpful to the local plants
C.soybeans, fruits and berries are favorites of aphids.
D.pecan trees are common in the south of America
（4）According to the experts, ladybugs are________.
A.more helpful than considered as pets
B.more pests than helpful insects
C.helpful as well as destructive
D.are more destructive than helpful

阅读理解
Oh my God, the robots are taking over! We're doomed! Doomed! Now that I've gotten that out of my system, it's become clear that while we may or may not be doomed, the robots are taking over. The latest example is the government's new guidelines for self-driving cars.
Tesla, Google and Uber are already testing driverless cars in cities across America. Uber chief executive Travis Kalanick is among those predicting that by 2021, self-driving cars will play a big part in urban settings.
Nearly 40,000 people died last year in this nation in automobile-related accidents, and we believe driverless cars can save tens of thousands of lives annually.
It makes sense. Robot drivers are less likely to get drunk, drive without a license, text while driving or feel agitated at the scene of a traffic jam. On the other hand, I wonder how these highly sensitive cars will react with walkers constantly dashing into the street. Will they jam on the brakes every 10 seconds?
But there's a bigger picture. Not only are robots replacing humans behind the wheel, but behind the work desk, in warehouses, senior homes, you name it. Robots aren't just taking over in the workplace.
The question is, where can't a robot function better than a human? How about writing songs? A robot can go through every combination of notes in record time and come up with a pleasing melody. The lyrics might be a different story. Is a Grammy-winning song co-written by Hank Human and R-3071 in our future?
Finally, it's only a matter of time until we have robot politicians and presidential candidates. Why not? They can be programmed to be experts in world and domestic affairs and come up with the best solutions without corruption and bad humors.
Actually, it's too bad such technology isn't available in 2018. Pretty sure the robot would win in a landslide.
（1）What does the underlined word “agitated” in Paragraph 4 mean?
A.Exhausted.
B.Embarrassed.
C.Disappointed.
D.Anxious.
（2）What doubt does the writer have about self-driving cars?
A.How passengers behave in it.
B.How robot drivers get the license.
C.How they respond to walkers on a busy street.
D.How they avoid crashing into other cars.
（3）The last question asked in Paragraph 6 reflects the writer's      .
A.eagerness to listen to songs written by robots
B.doubt about robots' ability to write songs
C.confidence in robots' winning Grammy Awards
D.curiosity about the future Grammy songs
（4）What might be the most suitable title for the text?
A.Robots will control the world in every field.
B.Robots can drive cars and write music.
C.Robots are being used in our daily life.
D.Robots are coming but not soon enough.