The scientists observed that the more junk food the rats ate, the more they wanted to eat – a behavior very similar to that of rats addicted(上了瘾的) to heroin, a dangerous drug. Johnson said the experiment shows that the brain chemistry of obesity(肥胖) and drug addiction may be quite similar.
In their experiment, Johnson and his team studied the “pleasure center” of rats’ brains. The pleasure center is a complicated network of nerve cells. If the animal exercises or eats, the cells reward the animal by releasing chemicals into the body that make it feel good. And when the body feels good, the animal – or person – will want to do the behavior again.
For the experiment, Johnson fed foods like cheesecake to one group of rats. Food like this is high in calories and fat. Another group of rats got a regular diet. The rats that ate junk food started to eat more and more.
“They’re taking in twice the amount of calories as the control rats,” says Paul Kenny, one of Johnson’s colleagues.
Kenny and Johnson wanted to know what was going on in the brains of these rats. They first designed a way to deliver a small electrical charge to the rats’ brains. This electrical charge would stimulate the pleasure centers to release pleasure-causing chemicals. The rats could control how much stimulation – and how much pleasure – they received by running on a wheel. The more the rat ran, the more pleasure it received.
The rats that had been eating junk food started running more and more. This behavior suggested that the junk-food-eating rats needed more brain stimulation to feel good compared with rats on a normal diet. In other words, their pleasure centers were becoming less sensitive and the junk food didn’t make them feel good unless they ate more and more.
Experiments like this one could help scientists understand how chemicals in the brain contribute to obesity. With that information, they may be able to help people avoid obesity in the first place.
(Note: Answer the questions or complete the statements in NO MORE THAN TEN WORDS.)
【小题1】 The scientists suggested it was actually ___________________ that made the rats feel good.
【小题2】 How did the scientist know what was happening in the brains of the junk-food-eating rats?
【小题3】What was the purpose of the experiment mentioned in the article?
【小题1】chemicals in the brain
【小题2】 By delivering a small electrical charge to the rats’ brains.
【小题3】To understand how chemicals in the brain contribute to obesity.
解析试题分析：本文主要叙述的是一项研究，研究人脑中的化学物质是如何控制我们的行为的，尤其是如何控制我们的肥胖的。
【小题1】chemicals in the brain
细节题。根据第二段2,3行If the animal exercises or eats, the cells reward the animal by releasing chemicals into the body that make it feel good.可知正是老鼠释放的化学物质让它感觉很好。
【小题2】 By delivering a small electrical charge to the rats’ brains.
细节题。根据文章第五段2,3行They first designed a way to deliver a small electrical charge to the rats’ brains. This electrical charge would stimulate the pleasure centers to release pleasure-causing chemicals.可知他们向老鼠的大脑里投放了一定数量的化学物质。以此来研究具体的反应。
【小题3】 To understand how chemicals in the brain contribute to obesity.
推理题。根据文章主体段第一段最后2行Johnson said the experiment shows that the brain chemistry of obesity(肥胖) and drug addiction may be quite similar.可知这个研究的目的在于理解头脑中的化学物质是如何导致我们的肥胖的。
考点：考察科普类短文阅读
名校课堂系列答案科目：高中英语 来源： 题型：阅读理解
How can we measure animals’ emotions? A new study of animal’s emotions suggests that, as in humans, emotions can tell animals about how dangerous their world is, and guide the choices that they make. The article of the study by Bristol University’s professor Mike Mendl was published online.
An animal living in an environment where it is often threatened by predators(捕食者）will develop a negative emotion or “mood”, such as anxiety. However, one in an environment with plenty of opportunities to get resources for survival will be in a more positive mood state.
The researchers say that these emotional states not only show the animal’s experiences, but also help it decide how to make choices, especially in unclear situations. This could have good or bad results. An animal in a negative mood state will make a safety-first with a “pessimistic” response to an unclear event. For example, it considers a noise in the grass as a signal of the predator. At the same time, an animal in a positive mood state will benefit from a more “optimistic” response. It considers the noise as a signal of prey(猎物）.
Professor Mike Mendl, head of the Animal Welfare and Behavior Research Group at Bristol University’s School of Clinical Veterinary Science said, “ We can use “optimistic” or “pessimistic”decision-making as a symbol of an animal’s emotional state. Recent studies by our group and others suggest that this is a meritorious new approach to studying a variety of animal species.”
“Public interest in animal welfare remains high, with widespread concern about the way in which animals are treated, used and included in society. To understand how animals should be treated, we need to better understand their emotional lives,” Mike Mendl said. The researchers believe Mike Mendl’s study can help them to better understand and assess an animal’s emotions.
【小题1】When an animal is in a negative mood state, _______.
| A．its response to an unclear event is pessimistic |
| B．it will pay little attention to an unclear event |
| C．it is easy for it to make right decisions |
| D．it has more opportunities to get food |
| A．valuable | B．useless | C．fashionable | D．hopeless |
| A．the animals with positive emotions live longer |
| B．there is no way to assess an animal’s emotions |
| C．few people care about animal welfare nowadays |
| D．the environment can influence animal’s emotions |
| A．tell people to build more protected areas for animals |
| B．explain animals should be regarded as people’s friends |
| C．raise people’s interest in studying animals |
| D．make people know how to treat animals properly |
| A．Different kinds of Animals’ Emotions |
| B．Emotions Helps Animals to Make Choice |
| C．The Living Environment of Wild Animals |
| D．The Best Way to Measure Animals’ Emotions |
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科目：高中英语 来源： 题型：阅读理解
Everyone has got two personalities—the one that is shown to the world and the other that is secret and real. You don’t show your secret personality when you’re awake because you can control your behavior, but when you’re asleep, your sleeping position shows the real you. In a normal night, of course, people frequently change their position. The important position is the one that you go to sleep in.
If you go to sleep on your back, you’re a very open person. You normally trust people and you are easily influenced by fashion or new ideas. You don’t like to upset people, so you never express your real feelings. You’re quite shy and you aren’t very confident.
If you sleep on your stomach, you are a rather secretive(不坦率的) person. You worry a lot and you’re always easily upset. You’re very stubborn(顽固的), but you aren’t very ambitious. You’re usually live for today not for tomorrow. This means that you enjoy having a good time.
If you sleep curled up (卷曲), you are probably a very nervous person. You have a low opinion of yourself and so you’re often defensive. You’re shy and you don’t normally like meeting people. You prefer to be on your own. You’re easily hurt.
If you sleep on your side, you have usually got a well-balanced personality. You know your strengths and weaknesses. You’re usually careful. You have a confident personality. You sometimes feel anxious, but you don’t often get depressed. You always say what you think even if it annoys people.
【小题1】According to the writer, you naturally show your secret and real personality .
| A．only in a normal night |
| B．only when you go to sleep |
| C．only when you refuse to show yourself to the word |
| D．only when you change sleeping position |
| A．He or she is always open with others. |
| B．He or she always likes new ideas earlier than others. |
| C．He or she is always easily upset. |
| D．He or she tends to believe in others. |
| A．He or she is careful not to offend others. |
| B．He or she doesn’t want to stick to his or her opinion. |
| C．He or she can’t be successful in any business. |
| D．He or she likes to bring others happiness. |
| A．He or she would rather be alone than communicate with you. |
| B．He or she is rarely ready to help you. |
| C．He or she prefers staying at home to going out. |
| D．He or she wouldn’t like to get help from you. |
| A．he or she always shows sympathy for people |
| B．he or she is confident, but not stubborn |
| C．he or she has more strengths than weaknesses |
| D．he or she often considers annoying people |
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科目：高中英语 来源： 题型：阅读理解
Ask someone what they have done to help the environment recently and they will almost certainly mention recycling. Recycling in the home is very important of course. However, being forced to recycle often means we already have more material than we need. We are dealing with the results of that over-consumption in the greenest way possible, but it would be far better if we did not need to bring so much material home in the first place.
The total amount of packaging increased by 12% between 1999 and 2005. It now makes up a third of a typical household’s waste in the UK. In many supermarkets nowadays food items are packaged twice with plastic and cardboard.
Too much packaging is doing serious damage to the environment. The UK, for example, is running out of it for carrying this unnecessary waste. If such packaging is burnt, it gives off greenhouse gases which go on to cause the greenhouse effect. Recycling helps, but the process itself uses energy. The solution is not to produce such items in the first place. Food waste is a serious problem, too. Too many supermarkets encourage customers to buy more than they need. However, a few of them are coming round to the idea that this cannot continue, encouraging customers to reuse their plastic bags, for example.
But this is not just about supermarkets. It is about all of us. We have learned to associate packaging with quality. We have learned to think that something unpackaged is of poor quality. This is especially true of food. But it also applies to a wide range of consumer products, which often have far more packaging than necessary.
There are signs of hope. As more of us recycle, we are beginning to realise just how much unnecessary material are collecting. We need to face the wastefulness of our consumer culture, but we have a mountain to climb.
【小题1】What does the underlined phrase “over-consumption” refer to?
| A．Using too much packaging. |
| B．Recycling too many wastes. |
| C．Making more products than necessary. |
| D．Having more material than is needed. |
| A．the tendency of cutting household waste |
| B．the increase of packaging recycling |
| C．the rapid growth of super markets |
| D．the fact of packaging overuse |
| A．helps control the greenhouse effect |
| B．means burning packaging for energy |
| C．is the solution to gas shortage |
| D．leads to a waste of land |
| A．Unpackaged products are of bad quality. |
| B．Supermarkets care more about packaging. |
| C．It is improper to judge quality by packaging. |
| D．Other products are better packaged than food. |
| A．Fighting wastefulness is difficult. |
| B．Needless material is mostly recycled. |
| C．People like collecting recyclable waste. |
| D．The author is proud of their consumer culture. |
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科目：高中英语 来源： 题型：阅读理解
The energy crisis has made people aware of how the careless use of the earth’s energy has brought the whole world to the edge of disaster. The over-development of motor transport, with its increase of more cars, more traveling, has contributed to the near-destruction of our cities and the pollution not only of local air but also of the earth’s atmosphere.
Our present situation is unlike natural disasters of the past. Worldwide energy use has brought us to a state where long-range planning is vital. What we need is not a continuation of our present serious state, which endangers the future of our country, our children, and our earth, but a movement forward in order to work rapidly and effectively on planetary problems.
This country has been failing back under the continuing exposures of loss of morality and the revelation(揭露) that lawbreaking has reached into the highest place in the land. There is a strong demand for morality to turn for the better and for some devotion that is vast enough and yet personal enough to enlist the devotion of all. In the past it has been only in a way in defense of their own country and their own benefits that people have been able to devote themselves wholeheartedly.
This is the first time that we have been asked to defend ourselves and what we hold dear in cooperation with all the other people of this planet, who share with us the same endangered air and the same endangered oceans. There is a common need to reassess our present course, to change that course and to employ new methods through which the world can survive. This is a priceless opportunity.
To grasp it, we need a widespread understanding of nature if the crisis we and the world are facing is no passing inconvenience, no byproduct of the ambitions of the oil-producing countries, no environmentalists’ only fears, no byproduct of any present system of government. What we face is the result of the invention of the last four hundred years. What we need is a transformed life style. This new life style can flow directly from science and technology, but its acceptance depends on a sincere devotion to finding a higher quality of life for the world’s children and future generation.
【小题1】Which of the following has nearly destroyed our cities?
| A．The loss of beliefs and ideas. |
| B．More of law-breaking. |
| C．Natural disasters in many areas. |
| D．The rapid growth of motors. |
| A．seriousness of this crisis |
| B．ineffectiveness of laws |
| C．similarity of the past to the present |
| D．hopelessness of the situation |
| A．Disregard for law. | B．Lack of devotion. |
| C．Lack of understanding. | D．Destruction of cities. |
| A．make a recommendation for a transformed life style |
| B．limit ambitions of the people of the whole world |
| C．demand devotion to nature and future generation |
| D．encourage awareness of the decline of morality |
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科目：高中英语 来源： 题型：阅读理解
Food prices have risen sharply over the past few years. The good news is that the rate of increase has slowed. The bad news is that prices will not go down anytime soon.
Also，the rate of global agricultural production is slowing. Yet it needs to increase 60% over the next 40 years to feed a growing world population.
These are among the findings from the OECDFAO(the Organization for Economic Cooperation and Development & the Food and Agriculture Organization)Agricultural Outlook(展望)2012－2021.
FAO DirectorGeneral Jose Graziano da Silva spoke at a news conference in Rome when the report was released. Mr.Da Silva said that，not surprisingly，the world's poorest people will feel the greatest effects of higher prices.
“For the millions and millions of extremely poor people， the effects of high food prices are clear—they might have to change their diets，usually to ones with poorer nutrition quality， ”he said.
In middleincome countries， people are gaining weight as they eat fewer fruits and vegetables and more of the cheaper but less nutritious foods.
The report also shows that farmers in poorer countries will be leading efforts to feed an expected 9,000,000,000 people by 2050.The outlook predicts that farmers in Latin America，the Caribbean and subSaharan Africa will drive agricultural production in the future.
Angel Gurria，SecretaryGeneral of the OECD，said：“We can feed 9,000,000,000 people by 2050 on this planet. But we have to organize ourselves better.” But there are plenty of challenges.Onefourth of all agricultural land is damaged. Many countries face water shortages(短缺)．And experts believe climate change is driving increasingly unusual weather patterns.
The report says farmers need to use more growing methods that can't cause damage to the environment.At the same time，it says governments should end economically harmful supports and spend more money to increase agricultural production.Mr.Gurria says rich and poor nations need to treat agriculture more like a business.
“In many cases，agriculture is related in people's minds to the poorest. It's related to aid. It's related to very poor living conditions，etc. We have got to shake that image away，”he said.
【小题1】Why are people gaining weight in countries with average incomes?
| A．They eat more food. | B．They eat less nutritious foods. |
| C．They eat cheaper fruits. | D．They eat cheaper vegetables. |
| A．are damaging a great part of their agricultural land |
| B．will play a great role in feeding the growing world population |
| C．are spending lots of money increasing agricultural production |
| D．will not be so seriously affected by food prices as rich nations |
| A．Improving the growing methods. |
| B．Finding more agricultural land. |
| C．Preventing governments' involvement. |
| D．Improving farmers' living conditions. |
| A．Agriculture means difficulty and sadness. |
| B．Food prices will go down in the near future. |
| C．It's almost impossible to feed 9,000,000,000 people by 2050. |
| D．Both rich and poor countries should take agriculture seriously. |
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科目：高中英语 来源： 题型：阅读理解
With the Tesla Roadster and other plugin (插入式) electric vehicles hitting the road，demand is growing for accessible refueling points to recharge(充电) them. Carbon Day Automotive, a Chicagobased company，has now demonstrated（演示）a solarpowered recharging point, known as the Solar PlugIn Station，which lets motorists easily charge their cars using electricity that has been produced without any environmental damage.
The Solar PlugIn Station has gone on show in Chicago as part of the city’s bid（竞标）to host the 2016 Olympic Games. According to Carbon Day Automotive，the Solar PlugIn Station on show in Chicago is part of the vital infrastructure(基础设施) required for electric vehicles in Chicago and was the focus of a recent visit by the International Olympic Committee.
These solarpowered electricity points will be used daily to fuel the city’s electric vehicles with power from the sun. By producing the electricity from pollutionfree solar cell, the CO2 emissions are reduced to zero.
“Solar energy and electric vehicles are a partnership that is one more step to reducing our dependence on foreign oil,” says Richard Lowenthal, CEO of Coulomb Technologies.Coulomb Technologies recently developed the components (部件) required for individual recharging stations，marketed as ChargePoint Networked Charging Stations.Carbon Day Automotive is the Midwest distributor for the ChargePoint stations. The Solar PlugIn Station consists of giant solar panels (电池板) that shade the tiny ChargePoint Networked Charging Station.The solar panel is connected to an underground battery pack，ready for everyday refueling.
“Without these stations it would be like driving around in a traditional car without the availability of gas stations，” says Scott Emalfarb，CEO at Carbon Day.“The day of true plugin electric vehicles will be here sooner than most people realize and the world needs to be ready to accommodate（为……提供场地）them.”
【小题1】The Solar PlugIn Station is used as part of the bid to host the Olympics mainly because ________.
| A．it’s environmentally friendly |
| B．it makes up for the lack of electricity |
| C．it’s a new idea and attracts people’s attention |
| D．it brings convenience to electric vehicle users |
| A．to recharge the electric vehicles takes a long time |
| B．the Solar PlugIn Station will come into use in 2016 |
| C．the Solar PlugIn Station has gone on show internationally |
| D．Chicago is promoting the use of electric vehicles |
| A．2. | B．3. | C．4. | D．5. |
| A．more visitors will come to Chicago |
| B．the citizens of Chicago will be able to go to work faster |
| C．more space for electric vehicles will be needed |
| D．the cost of electric vehicles will be lower than traditional cars |
| A．Chicago Will Soon Be Full of Electric Vehicles |
| B．Chicago Calls on People to Buy Electric Vehicles |
| C．Chicago Fights for Its Bid to Host the 2016 Olympics |
| D．Chicago Shows Its Solarpowered Recharging Stations |
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科目：高中英语 来源： 题型：阅读理解
Popeye the Sailor first became a popular cartoon in the 1930s.The sailor in that cartoon ate lots of spinach to make him strong. People watched him, and they began to buy and eat a lot more spinach. Popeye helped sell 33 percent more spinach than before! Spinach became a necessary part of many people’s diets. Even some children who hated the taste began to eat the vegetable.
Many people thought that the iron in spinach made Popeye strong, but this is not true. Spinach does not have any more iron than any other green vegetable.
People only thought spinach had a lot of iron because the people who studied the food made a mistake. In the 1890s, a group of people studied what was inside vegetables. This group said that spinach had ten times more iron than it did. The group wrote the number wrong, and everyone accepted it.
Today, we know that the little iron there is in spinach cannot make a difference in how strong a person is. However, spinach does have something else which the body needs—folic acid.
It is interesting to point out that folic acid can help make a person strong. Maybe it was really the folic acid that made Popeye strong all along.
【小题1】Why did many people eat spinach after they saw Popeye the Sailor?
| A．They thought spinach made them strong. |
| B．They thought Popeye was funny. |
| C．Spinach had a lot of iron. |
| D．People liked folic acid. |
| A．made Popeye strong |
| B．was a green vegetable |
| C．had less iron than other green vegetables |
| D．had more iron than other green vegetables |
| A．iron | B．folic acid | C．spinach | D．exercise |
| A．something in food | B．a vegetable | C．dangerous | D．a certain kind of spinach |
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科目：高中英语 来源： 题型：阅读理解
A study shows that nearly ninety percent of teens report that they have tried alcohol. That’s an increase of 23 percent in just four years!
Each year, 1.1 billion cans of beer are drunk by students aged 15-19 years old. Beer is the most common alcoholic drink among teens—81 percent of the drinkers had tried it. Beer is followed by wine with 63 percent, hard liquor(烈酒) with 53 percent and wine coolers with 35 percent.
When the young people are asked why they drank, the most common answer is that drinking is “something to do”. If a teen’s parents drink alcohol, the teenager is more likely to start drinking at an early age. Also, tens see all of their friends drinking alcohol so they think it is the must-to-do thing. Peer pressure is probably the hardest thing teens have to deal with. What’s more, teens often drink alcohol because it makes them feel older and cooler.
Researchers asked 56,000 students about their drinking habits and grades, to see how drinking might affect their grades in school. The results seem to be clear. Students who got a C level or lower tend to use three times as much alcohol as those who got B’s or A’s.
Alcohol use can be deadly. About 8,100 young people are killed per year in alcohol-related accidents. Eight young people die per day as a result of a drunk-driving accident. Between 50 and 65 percent of all teen suicides (自杀) occur after the young people drink.
So you see, drinking the alcohol doesn’t always end up with a good time. The next time you try to push someone to drink or someone tries to push you to drink, please remember this. One drink can set the habit for life. Why not throw it away?
【小题1】The reasons for teens’ drinking alcohol are mentioned EXCEPT that _______________.
| A．they think it is cool to drink alcohol |
| B．their parents set a bad example to them |
| C．alcohol can make them happier |
| D．peer pressure plays an important role |
| A．Drinking alcohol makes students stupid. |
| B．Good students never try alcohol. |
| C．Drinking habits have something to do with IQ. |
| D．Students with poor grades tend to use more alcohol. |
| A．show the bad effect of drinking alcohol |
| B．show how many teenagers drink alcohol |
| C．tell teenagers not to try alcohol |
| D．tell the reasons why teenagers drink alcohol. |
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