Scientists have been puzzled by the phenomenon that migrating birds fly not just in groups all the time, but in "V" formations and they have tried to figure out what benefit birds get from this particular formation. Now, a research group from University of London may have found the answer ― migrating birds fly in a "V" to save energy, according to a study published in the journal Nature.
When a bird flaps(振翅) its wings, it stirs the air around it and causes it to move indifferent directions. Scientist found in the study that the air creates an upward-moving wave at the tips of the wings, which means that if a bird flies around the wingtips of another bird, it can get a boost（抬高） from the rising air and therefore use less energy to stay in the air.
Apart form the "free ride" strategy, scientists were also surprised to observe that migrating birds timed their wing beats and adjusted their positions in a very precise way to maximize the lifting effect while avoiding areas where the air move downward.
"They're able to sense what's going on from the bird in front, where this 'good air' is coming from and now how to position themselves perfectly in it," lead researcher Steven Portugal told BBC.
In fact, the "V" formation has long thought to help birds fly more efficiently(效率搞地). A previous study showed that birds' heart rates went down when they were flying together in a "V" formation. Jet fighters were also found to be able reduce their energy use by up to 18% by staying near the wingtips of other jet fighters. Both of these findings led scientists to suspect that the "V" formation had an efficiency purpose, but until now they still lack proof.
"For scientists, the new study provides an insight into an interesting natural phenomenon. But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."
小題1:What is the author's purpose in writing this article?
A．To explain how birds benefit from migration.
B．To introduce how migrating birds find their way.
C．To tell some applications of migrating birds' "V" formations.
D．To report new findings about migrating birds' "V" formations.
小題2: According to the recent study, when birds migrate        .
A．they don't change their lead birds during the whole journey
B．they fly in "V" formations to protect themselves against enemies
C．they form the shape of a "V" to make best use of the lifting effect
D．the air they stir around makes it hard for the birds behind to fly fast
小題3:What is the significance of the new study according to this article?
A．It might inspire aircraft companies to think of ways to improve efficiency.
B．It has proved that the "V" formation can improve in efficiency in many fields,
C．It has led scientists to discover that birds' heart rates go down when they fly in a "V".
D．It shows that the best formation of jet fighters in battle should be a "V" formation.
小題4: The underlined word "imitate" in the last paragraph most probably means "        ".
A．useB．copyC．changeD．learn

小題1:D
小題2:C
小題3:A
小題4:B
本文介紹的是一項新的研究，是關(guān)于候鳥使用V字形飛行的原因。以此對我們的飛機制造有些啟發(fā)作用。
小題1: D
【試題解析】推理題。根據(jù)文章主題段第一段最后一句Now, a research group from University of London may have found the answer ― migrating birds fly in a "V" to save energy, according to a study published in the journal Nature.可知本文是對候鳥使用V字形飛行的原因的研究的新的發(fā)現(xiàn)。故D正確。
小題2: C
【試題解析】推理題。根據(jù)文章第三段Apart form the "free ride" strategy, scientists were also surprised to observe that migrating birds timed their wing beats and adjusted their positions in a very precise way to maximize the lifting effect while avoiding areas where the air move downward.可知候鳥按照V字形飛行是為了更好地利用鳥兒拍打翅膀帶來的lifting的影響，讓飛行的效率更高。故C正確。
小題3: A
【試題解析】推理題。根據(jù)文章最后2行. But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."可知飛機制造商可以利用這一研究結(jié)果來提高飛機飛行的效率。故A正確。
小題4: B
【試題解析】猜測詞義題。根據(jù)本句But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."可知這一新發(fā)現(xiàn)能夠幫助那些飛機制造商，更好地理解他們?nèi)绾文７馒B兒的這一飛行特點來改造飛機以節(jié)省燃料。該該詞是指“模仿”，故B正確。
【長難句解析】
Scientists have been puzzled by the phenomenon that migrating birds fly not just in groups all the time, but in "V" formations and they have tried to figure out what benefit birds get from this particular formation.
【翻譯】科學家對于這一現(xiàn)象感覺很困惑，候鳥飛行的時候不僅僅是一直都是一群鳥兒一起飛而且是按照V字形在飛行。他們一直都想知道從這種特殊的飛行模式中鳥兒能夠得到什么樣的好處。
【分析】本句中有一個同位語從句that migrating birds fly not just in groups all the time, but in "V" formations，對前面的名詞the phenomenon進行解釋說明，that在這個同位語從句中不充當任何成分，只是一個引導詞而已。同時動詞figure后面還有一個由what引導的賓語從句，what在賓語從句中做主語。
練習冊系列答案
相關(guān)習題

科目：高中英語 來源：不詳 題型：閱讀理解

     Say you're in the wine store and you want to buy something new. You have nothing to go by outside of the label. Will the label tell you anything you should know? Here's some general advice:
Vintage. This is the first thing we look for ourselves. You don't need to care whether 2001 or 2002 was a better year in the Sierra Foothills. The vast majority of wines at the store are meant to be drunk right away, so you make sure the wine isn't too old, particularly if you're buying it expecting lively, fresh fruitiness. We often see five-year-old Pinot Grigio and two-year-old Beaujolais Nouveau at stores, for example, so as soon as we see that kind of age on wines like those, we know we can skip them and move on(and possibly not shop there again).
Alcohol content. Too many wines have too much alcohol, which leaves them unbalanced. Sure, there are some classic wines with high alcohol levels, but many of today's regular table wines--Merlot, Chardonnay--have levels at 15% or above. Some of those might be terrific, but if we had nothing else to go on, we'd look for alcohol content at about 14% and below.
The more specific the better. A wine that says it's from Napa is probably a better bet than a wine that simply says it's from California. Unfortunately, this will also probably be reflected in the price, so this might not tell you much about value, If you care enough to know a few of famous vineyards for producing high-quality grapes, they might help you make an educated guess about quality.
Old vines. Theoretically, older vines produce fewer, but more flavorful grapes, but the problem is that no one has defined what an "old vine" is, so anyone can put this on the label. Just ignore it.
A phone number. You'd be surprised many small-production wines these days include a phone number on the back and an invitation to call the winerY, which is a sign of a highly personal winerY. We have called those numbers many times over the years and it's amazing how often the winemaker or winerY owner answers the phone.
小題1: The underlined word "Vintage" in the second paragraph probably means "________ " .
A．the place where the wine was madeB．the year when the wine was made
C．the freshness of the wineD．the label of the wine
小題2:It's better to buy
A．five-year-old Pinot GrigioB．the wine labeled from older vines
C．the wine from famous vineyardsD．two-year-old Beaujolais Nouveau
小題3: From the passage we Can infer that
A．the wine with high alcohol levels is definitely terrific
B．most wines at the store are intended to be drunk right away
C．older vines have lower production
D．some winemakers keep the promise all the time
小題4: What is paragraph 4 mainly about?
A．Geography.B．PriceC．Quality.D．Grapes.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

It's wonderful to go to another country, complete a volunteer project and feel that you really have a positive influence. But how can you become an international volunteer?
* Plan practically. Contact the organization a few months before leaving and find out if there are materials which are rare and hard to attain for the project. What you often consider plentiful here, such as nails or hammers, is in great need in other parts of the world.
* Do the project together, not on your own. You are a guest in the community. The most successful result is not that you build something and walk away, but that you and the community build something as a team. Share skills and build together.
* Be flexible. Not everything is going to happen as planned. Often the other country doesn't have the right tools, manpower, transportation or funds to get all the needed work done. In a word, they lack infrastructure(基礎(chǔ)設(shè)施).
* Contact with the people in the community. Often you will have "downtime" outside of the range of the project. Rather than retreat to the group with whom you traveled, be sure to spend time with the people of the community. Listen to the things about their lives. If you can't speak the language, smiles work wonders. And you will be surprised ― you will find a way to community.
Volunteering is a special and life-long experience for everyone involved. Be prepared that the person who may be changed most is you. It's a joyful, often careful experience which will encourage you to view yourself, your neighbors and your world quite differently.
小題1: When you volunteer to join in a project, you are advised to          .
A．build something and walk away
B．make good preparation in advance
C．a(chǎn)void involving locals in activities
D．depend on yourself to solve problems
小題2: According to the author, volunteer will          .
A．reduce challenge in the world
B．determine the future of a volunteer
C．change a person's opinion of the world
D．benefit volunteers most in their learning
小題3: What is the passage mainly about?
A．What prepares you to become a volunteer.
B．Where volunteers are needed most in the world.
C．Why volunteering is popular with young people.
D．How volunteers develop a relationship with local people.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

Depression (抑郁癥) is a serious problem today.Depression causes workers to be unproductive，causing companies and countries to lose billions of dollars.One expert says that depression is like cancer because it is “widespread，costly and deadly”．Depression hits one person in five around the world.
Although people have believed depression to be a problem among the rich and educated，studies show that depression is a problem among everyone.Over any six­month period，between five to seven percent of the world’s population will be suffering from a serious depression.Suicide rates among people suffering from the disease in its extreme，or clinical form were 80 percent higher than in the population at large，and sufferers were four times more likely to have heart attacks.People who suffer from depression often have problems sleeping，getting up on time，and doing work productively.
Depression，which researchers agree has its origin in the genes，brings loss of confidence and ability to concentrate—making it impossible for employees and managers to work efficiently.
Depression is made more serious in China by Chinese’s inability to face it.Many people believe that depressed people are either weak or lazy.Besides，there is no good treatment，with few specialists available.“Most patients in China just don’t get help，”a Chinese doctor says.“In my hospital，I have to see 30 or 40 patients in a morning，just have time to say ‘Hello，how do you feel？’”
In Western countries，people are not afraid to admit that they have depression，but most do not tell it to their boss，because they fear that they will be stricken_off_the_rolls.“In my experience，aging bosses are the most willing to admit they have it.Because they feel the most secure about themselves，” an American doctor says.
Hopefully，in the near future，people around the world will be able to admit that they have depression so that they can get the right treatment.
小題1:Which of the following is true according to the passage?
A．It is widely believed that everyone may suffer from depression.
B．Depression brings great problems to its sufferers in their life and work.
C．Depression is a commonly­existing problem only in rich countries.
D．The poorer and the less educated a person is，the less he will suffer from depression.
小題2:．Compared to normal people，the depressed people are likely to be________.
A．very unconfident and often absent­minded
B．easy to avoid being hit by heart attacks
C．working efficiently and productively
D．either weak or lazy
小題3:Depression becomes more serious in China because of________.
A．the understanding of the problem
B．the lack of treatment and doctors
C．their unwillingness to tell it to their boss
D．the doctors’ careless work
小題4:What can we infer from the passage?
A．People are suffering from depression because of the shortage of specialists.
B．The aging bosses around the world dare to say they are depressed.
C．More and more patients will turn to specialists for help.
D．Western people are braver than Chinese people.
小題5:What does the underlined words in the 5th paragraph mean?
A．Hired.B．Dismissed.
C．Promoted.　D．Recommended.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

Holidays
Holiday News
Vacancies(空位) now and in the school holidays at a country hotel in Devon. This comfortable, friendly home-from-home lies near the beautiful quiet countryside, but just a drive away from the sea. The food is simple but good. Children and pets are welcome. Reduced prices for low season.
 
The snowdonia Centre
The Snowdonia Centre for young mountain climbers has a mountain climbing lesson. The beginners’ costs are ￡57 for a week, including food and rooms. Equipment is included except walking shoes, which can be hired at a low cost.
You must be in good health and prepared to go through a period of body exercises. This could be the beginning of a lifetime of mountain climbing adventure.
 
The World Sea Trip of a Lifetime
Our World Sea Trip of 2008 will be unlike any holiday you have ever been on before. Instead of one hotel after another, with all its packing and unpacking, waiting and traveling, you just go to bed in one country and wake up in another.
On board the ship, you will be well taken care of. Every meal will be first-class and every cabin like your home.
During the trip, you can rest on deck(甲板), enjoy yourself in the games rooms and in the evening dance to our musical team and watch our wonderful play.
You will visit all the places most people only dream about — from Acapulco and Hawaii to Tokoy and Hong Kong.
For a few thousand pounds, all you’ve ever hoped for can be yours.
 
 
68. What can you do if you like to go on holidays with pets?
A. Choose the holiday in Devon.           B. Go to the Snowdonia Centre.
C. Join the World Sea Trip of 2008.       D. Visit Acapulco and Hawaii.
69. In what way is the Snowdonia Centre different from the other two holidays?
A. It provides chances of family gatherings.
B. It provides customers with good food.
C. It offers a sports lesson.
D. It offers comfortable rooms.
70. What is special about the World Sea Trip of 2008?
A. You can have free meals on deck every day.
B. You can sleep on a ship and tour many places.
C. You will have chances to watch and act in a play.
D. You have to do your own packing and unpacking.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

A world-famous Canadian author, Margaret Atwood, has created the world’s first long-distance signing device(裝置), the LongPen.
After many tiring……from city to city, Atwood thought there must be a better way to do them . She hired some technical experts and started her own company in 2004. Together they designed the LongPen. Here’s how it works: The author writes a personal message and signature on a computer tablet(手寫板) using a special pen. On the receiving end, in another city, a robotic arm fitted with a regular pen signs the book. The author and fan can talk with each other via webcams(網(wǎng)絡(luò)攝像機) and computer screens。
Work on the LongPen began in Atwood’s basement(地下室). At first, they had no idea it would be as hard as it turned out to be. The device went through several versions, including one that actually had smoke coming out of it. The investing finally completed, teat runs w ere made in Ottawa, and the LongPen was officially launched at the 2006 London Book Fair. From here , Atwood conducted two transatlantic book signings of her latest book for fans in Toronto and New York City.
The LongPen produces a unique signature each time because it copies the movement of the author in real time. It has several other potential applications. It could increase credit card security and allow people to sign contracts from another province. The video exchange between signer and receiver can be recorded on DVD for proof when legal documents are used.
“It’s really fun”, said the owner of a bookstore, who was present for one of the test runs. “Obviously you can’t shake hands with the author but there are chances for a connection that you don’t get from a regular book signing..
The response to the invention has not been all favorable. Atwood has received criticism from authors who think she is trying to end book tours. But she said, “It will be possible to go to places that you never got sent to before because the publishers couldn’t  afford it.”
小題1:Why did Atwood decide to invent the LongPen?
A. To set up her own company
B. To win herself greater popularity
C. To write her books in a new way
C. To make book signings less tiring
小題2:How does the LongPen work?
A．I copies the author’s signature and prints it on a book.
B．It signs a book while receiving the author’s signature.
C．The webcam sends the author’s signature to another city.
D．The fan uses it to copy the author’s signature himself.
小題3:What do we know about the invention of the LongPen?
A．It has been completed but not put into use.
B．The basement caught fire by accident.
C．Some versions failed before its test run.
D．The designers were well-prepared for the difficulty.
小題4:How could the LongPen be used in the future?
A．To draft legal documents.
B．To improve credit card security
C．To keep a record of the author’s ideas.
D．To allow author and fan to exchange videos
小題5:What could be inferred from Paragraphs 5 and 6?
A．Atwood doesn’t mean to end book tours.
B．Critics think the LongPen is of little use
C．Bookstore owners do not support the LongPen
D．Publishers dislike the LongPen for its high cost

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

As we know, the earth's climate has changed over time.The present rate of climate change depends, in large part, on human activities.Today, people all over the world are making everyday choices that help the environment.Small actions matter.In other words, climate change is your business.
A woman in Nicaragua buys fluorescent (熒光的) light bulbs that are 80 percent more energy­saving than traditional ones. Many  governments are now subsidizing energy­saving lights to encourage people  to turn to them.Consumers are discovering that the new­generation bulbs   help them save money in the long run.
Agriculture accounts for about 14 percent of global greenhouse gas emissions (排放) , and transporting the food around adds to the environmental cost.There is a team of young vegetable growers in the United Kingdom who want to encourage kids to start planting their own fruit and vegetables.
A young lawyer wearing business clothes rides her bicycle to work in a large U．S.city.She's been biking to work every day for the past two years and says it's a lot easier than many people think.A recent study shows that more Americans bike or walk to work today than before.
A university student from southeastern China carries a reusable shopping bag to cut back on disposable (一次性的) plastics.Some large shopkeepers have removed paper and plastic bags, and consumers are responding.
In Canberra, Australia, summers are hot and winters cold.To save electricity, Adam Wilson in Canberra uses an energy­saving heating system, and he keeps the temperature lower than he did in years past.He still makes it through the summer without air conditioning.
小題1:The passage mainly tells us that________.
A．climate change is concerned with everyone
B．the global warming is getting worse
C．saving energy is of great necessity
D．human is to destroy the environment
小題2:The underlined word “subsidizing” in Paragraph 2 probably means “________”．
A．chargingB．producing
C．giving allowance toD．taking advantage of
小題3:According to the passage, which of the following is TRUE?
A．The governments don't expect consumers to use the new­generation bulbs.
B．Agriculture should be responsible for part of the global gas emissions.
C．Many people in Nicaragua go to work on foot or by bike.
D．University students from China always carry disposable shopping bags.
小題4:We can learn from the last paragraph that________.
A．the climate in Canberra is mild all the year round
B．a(chǎn)n energy­saving heating system will come into use
C．Adam Wilson has a good habit of saving energy
D．Adam Wilson is skilled in inventing the energy­saving equipment

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

We sometimes think global warming or climate change is a problem very far away from our lives, and that only the government needs to worry about it. But it's hardly possible to completely stay out of it ­ scientists are now 95 percent sure that humans have been the “dominant cause” of global warming trends since the 1950s.
One of the conclusions of a report released on Sept 27 by the United Nations says that human activities have caused global temperatures to rise by 0.89 0C between 1901 and 2012. That might not seem like a lot, but the truth is that a major part of that heat has been absorbed into the oceans, which is not surprising given that they cover two thirds of Earth's surface. Also, water has a much greater capacity (容量) to absorb heat than the air does, according to The Economist.　
While many greenhouse gases occur naturally and are needed to keep the Earth warm enough to support life, humans' use of fossil fuels is the main source of excess (多余的) greenhouse gases. According to CNN, by driving cars, using electricity produced by burning coal and oil or heating our homes with coal or natural gas, we release a large amount of greenhouse gases into the atmosphere.
Your body can barely feel a difference of 0.89 0C, but the Earth's ecosystems are so sensitive that even small changes can disturb them. It often starts with the smallest creatures at the bottom of the food chain, eventually affecting bigger animals, many of which could end up becoming extinct.
Global warming is also linked to an increase in extreme weather. A larger amount of carbon dioxide traps more energy inside the atmosphere. This changes the patterns of storms and rainfall in many regions and can lead to droughts and floods. Worse still, melting sea ice in warmer oceans is causing sea levels to rise at a speed of more than three millimeters per year, according to The Guardian, which also increases the risk of flooding.
“The report should serve as another wake­up call that our activities today have a profound impact on society, not only for us, but for many generations to come，” French Michel Jarraud, secretary­general of the World Meteorological Organization, said at a news conference.
小題1:The underlined word “dominant” in the first paragraph means “ ________”．
A．common　　　　 　　　B．indirect
C．secondaryD．leading
小題2:Which of the following statements is TRUE according to the passage?
A．Greenhouse gases have been proven to harm merely the Earth .
B．There is little we can do to prevent global warming.
C．Global warming can increase the chances of droughts and floods.
D．The hugeness of oceans makes them better absorbers of heat than the air.
小題3:The rise in global temperatures between 1901 and 2012 ________.
A．is more harmful to smaller creatures than bigger ones
B．is not serious because most of the extra heat has been absorbed by the oceans
C．has made the Earth's ecosystems more sensitive to changes
D．is likely to cause many species to become extinct
小題4:What is Michel Jarraud's attitude toward the report released by the UN?
A．Negative.B．Supportive.
C．Doubtful.D．Uninterested.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

IT’S never a real problem for us when the weather gets cold. We can put on more clothes, stay next to a fireplace, turn on the air conditioner or simply travel to a warmer city to spend the winter – people have many different ways of coping with the cold.
But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat to keep themselves warm. So how do they manage to survive the freezing winter?
It turns out that plants have their own strategies too, said a study published on Dec 22 in the journal Nature.
According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite (凍瘡),” Zanne told Science Daily. Also, the process of freezing and thawing (解凍) can cause air bubbles to form in the plant’s water transport system. “If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant,” she explained.
To live through cold weather, plants have developed three traits, according to the study. Some plants, such as oak trees, avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves – and growing new leaves and water transport cells when the warm spring returns.
Other plants, pine trees for example, protect themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.
The third strategy is also the most extreme – some plants die on the ground in winter and start growing as new plants from seeds when conditions get warmer.
However, the study also found that these smart strategies were developed very slowly – over millions of years of evolution. This leads scientists to worry that plants may not be able to deal with human-caused climate change, which has only started occurring over the past few decades.
Scientists are hoping that this study can help people find possible ways to save plants from the threat of climate change.
小題1:What is the article mainly about?
A．Why plants are not afraid of the winter chill.
B．The ways that plants survive cold weather.
C．Changes in plants’ water transport system in winter.
D．How plants evolve to keep up with climate change.
小題2:According to the article, if a plant freezes in the winter, ______.
A．it produces more living tissues to stay alive
B．its leaves quickly fall out and its roots begin to die
C．lots of air bubbles form in its water transport system
D．its water transport system could be blocked in the spring
小題3:How do oak trees usually survive the cold winters?
A．By dropping their leaves before winter.
B．By narrowing their water transport cells.
C．By widening their water transport cells.
D．By leaving only the seeds alive and growing from the seeds in the spring.
小題4:What are scientists worried about when it comes to plants according to the article?
A．Plants may not be able to adapt to the increasingly cold climate.
B．Human activities might have a great impact on the pace of plants’ evolution.
C．Plants may not be able to evolve fast enough to adapt to human-caused climate change.
D．The strategies plants develop are not good enough to protect them against cold.

查看答案和解析>>

同步練習冊答案