It is a mystery that has puzzled doctors for decades. But experts believe they have now finally solved the tricky question of why winter is notoriously known as the flu season.

According to a new research, the influenza virus coats itself in a protective fatty shield that is tough enough to resist cold temperatures. The butter-like material only melts when it hits the respiratory tract（呼吸道）, leaving the virus free to infect cells-- a process scientists say is like an M&M melting in the mouth.

However, in warmer outdoor temperatures, the protective coating melts before it reaches a person or an animal, killing the bacteria before they can infect someone. Joshua Zimmerberg, from the National Institute of Child Health and Human Development (NICHD), in the US, which led the study, said: “Like an M&M in your mouth, the protective covering melts when it enters the respiratory tract. It's only in this liquid period that the virus is able to enter a cell to infect it.”

In the past, scientists worked on theories that flu is more common in winter because people spend more time inside or the radiation from the sun in summer kills off germs. But no research successfully explained the spread of the disease.

Researchers have already claimed that the report, which is published in the journal Nature Chemical Biology, could lead to new ways to prevent and treat flu. “Now that we understand how the flu virus protects itself so that it can spread from person to person, we can work on ways to prevent it.”

Influenza and other respiratory viruses are spread in small drops broadcast by coughing, sneezing and talking and which can also settle onto surfaces, to be picked up on fingertips.

1. What can be the best title of the passage?

  A. The mystery that has puzzled doctors for decades.    B. New ways to prevent and treat flu.

  C. A discovery of how flu strikes in Winter.            D. Ways found to prevent flu.

2. Which of the following statements is NOT true?

  A. Doctors have been trying hard to discover why flu strikes in winter.

  B. In the past, scientists didn’t know how flu spreads.

  C. It is possible that flu virus will no longer threaten humans in winter.

  D. People get affected by flu because they spend much more time inside in winter.

3. Where should you insert the following paragraph into the passage?

Duane Alexander, the director of NICHD, said: “The study results open new avenues of research for thwarting (使…受挫)winter flu outbreaks.”

  A. Between Paragraphs 1 and 2.     B. Between Paragraphs 3 and 4. 

  C. Between Paragraphs 4 and 5.     D. Between the last two paragraphs.

4.In what process or order does flu occur?

  a. The virus infects cells                 b. The influenza virus was born

  c. The butter-like material melts           d. The virus hits respiratory tract

  e. The virus coats itself in butter-like shield  f. The virus is free

  A. a, c, d, e, b, f .     B. c, f, d, b, e, a.    C. b, e, d, c, f, a.    D. d, b, e, c, f, a.

【小題1】C

【小題2】D

【小題3】D

【小題4】C

練習(xí)冊系列答案
相關(guān)習(xí)題

科目：高中英語 來源： 題型：閱讀理解

Pulling heavy suitcases all day in the summer is hard work, especially when you’re a thin 14-year-old. That was me in 1940―the youngest and smallest baggage boy at New York City’s Pennsyl­vania Railway Station.

After just a few days on the job, I began noticing that the other fellows were overcharging pas­sengers. I’d like to join them, thinking, “Everyone else is doing it.”

When I got home that night, I told my dad what I wanted to do. “You give an honest day’s work,” he said, looking at me straight in the eye. “They’re paying you. If they want to do that, you let them do that.”

I followed my dad's advice for the rest of that summer and have lived by his words ever since.

Of all the jobs I've had, it was my experience at Pennsylvania Railway Station that has stuck with me. Now I teach my players to have respect for other people and their possessions. Being a member of a team is a totally shared experience. If one person steals, it destroys trust and hurts everyone. I can put up with many things, but not with people who steal. If one of my players were caught stealing, he'd be gone.

Whether you’re on a sports team, in an office or a member of a family, if you can’t trust one another, there’s going to be trouble.

68. What can be inferred about the baggage boys?

A. They could earn much, but they had to work hard.

B. Many of them earned money in a dishonest way.

C. They were all from poor families.

D. They were all thin, young boys.

69. What does the father's advice imply?

A. It is wrong to give more pay to the passengers.

B. Don’t believe them if they are paying you more.

C. Don’t follow others to overcharge the passengers.

D. It is difficult to work hard and live as an honest boy.

70. The writer can't put up with stealing because he thinks that ______.

A. it is a totally shared experience

B. it is considered as the most dangerous

C. it does great harm to human relationship

D. it may lead to the loss of his sports team

71. It can be concluded from the text that ______.

A. his father's advice helped him to decide which job to take up

B. working in the sports team was his most important experience

C. he learnt much from his shared experience with his team members

D. his experience as a baggage boy had a great influence on his later life

查看答案和解析>>

科目：高中英語 來源：2013-2014學(xué)年廣東省山一高三上學(xué)期第二次統(tǒng)測英語試卷（解析版） 題型：閱讀理解

While I was in my 4th month of pregnancy (妊娠期) with my second child, we were preparing for a trip to Louisiana, where Marshall’s family live, to celebrate Jane’s 2nd birthday. Two days before we were to leave, we got the shocking news that I was going to lose the baby. Not knowing when this would happen, we decided to continue with our trip.

Since Marshall’s family lives on a 600-acre cattle farm, you often find that you have a lot of time to yourself to think when you are there. That is precisely what I did not want to do at this time. I told Marshall that I needed to get a good book to get lost in while I was there. I told him I heard the Harry Potter books were good, so he went out and got the first one for me.

During that trip, I totally got lost in the book, which was of great help during a time when I needed a distraction to forget about the sadness. In the book, I noticed the name “Seamus”. I vaguely remembered it was pronounced “Shamus” and I liked the sound of that. I mentioned it to Marshall and he liked it too. Toward the end of the trip, I had just 5 chapters left and I knew I was about to finish the first book, which I was pretty excited about.

Soon after we put Jane down to bed, I had started labor (分娩), so I was unable to read. The labor lasted 5 and 1/2 hours, but Marshall stayed there with me, sitting beside me and reading aloud the last 5 chapters of Harry Potter. I can never fully explain how much that helped me through the experience. And ever since then, Marshall and I both have been fans of the Harry Potter books. We remember how they helped us get through that time of our lives.

We were sad to have lost the baby, but the name Seamus started our journey toward adoption. And we gave this name to our adopted son. Though our Seamus doesn’t have a drop of Irish blood in him, the name fits him perfectly.

1.Why did the writer want a good book during the trip?

A. Because the trip to Louisiana would take a long time.

B. Because she didn’t want to think of losing her baby.

C. Because she had nothing else to do except reading.

D. Because a good book could help her enjoy her trip.

2.According to the story, we can know that the Harry Potter books _________________.

A. made the family’s trip more exciting

B. include five books all together

C. have someone called Seamus in them

D. can help people deal with their problems

3.The writer named her son Seamus because ___________________.

A. she wanted to keep her trip in memory

B. she loved this name very much

C. her son doesn’t have Irish blood

D. it is a perfect name for a boy

4.Which of the following is TRUE about the couple?

A. They planned their trip after getting the shocking news.

B. They thought the cattle farm was too large to do anything on.

C. They felt excited when they almost finished the trip.

D. They liked reading Harry Porter very much after the trip.

5.Which is the best title for the passage?

A. Funny Stories Of My Family           B. Seamus And Harry Potter

C. How We Got To Louisiana              D. How My Son Got His Name

 

查看答案和解析>>

科目：高中英語 來源：2012-2013學(xué)年安徽省合肥市高三第一次教學(xué)質(zhì)量檢測英語試卷（解析版） 題型：閱讀理解

My grandma whom we all called Nanny was a solid, first-generation, Italian immigrant. She came to this country with her family on a tiny ship during World War I when she was only 8 years old. During the trip she survived stormy seas，little food, and an attack by a German U-boat. After getting here，her large family worked hard to build a new life in America. They never had much money but were rich in love.

One day，when I was about 5 or 6 years old, my parents and brothers went on a trip. It was just me and Nanny in the house for the weekend. Nanny seemed so happy to be taking care of me all by herself. She made me a special breakfast that first morning. However, all I could do was to complain about how the food was not how Mom always made it. Nanny quietly put down the plate and went into the living room. I followed a minute later and saw that she had tears in her eyes. It was the first time I had ever seen my strong and proud grandmother cry and I was the one who had caused it.

I walked over to Nanny, climbed on her lap, and for the first time in my short life I did something else too. I apologized without being told to and asked Nanny to forgive me. She smiled, rubbed my head, and told me I was a good boy even though I didn’t feel like one then.

That memory just like my Nanny’s love will stay in my heart forever. It is a sign of both strength and wisdom. Asking for forgiveness helps us to learn, to grow, and to love.

1.Nanny，s family immigrated to America mainly because _____.

A．they suffered starvation in their homeland

B．they wanted to start a rich life in the new land

C．they tried to get away from the terrible climate

D．their country was in war and they needed peace

2.The boy complained to Nanny that the food _____.

A．wasn't cooked the way his mom did

B．was served a bit later than usual

C．was prepared in a special way

D．was just to his parents，taste

3.When seeing Nanny crying in the living room, the author felt _____.

A．surprised          B．a(chǎn)shamed          C．shocked           D．a(chǎn)nnoyed

4.The author mainly wants to tell us that _____.

A．forgiveness can be beneficial to people asking for it

B．hardships can make children more indifferent

C．grandparents are more tolerant than their grandchildren

D．family ties can sometimes be misused

 

查看答案和解析>>

科目：高中英語 來源：安徽省2010年高三下學(xué)期教學(xué)質(zhì)量檢測英語試卷（三） 題型：閱讀理解

第三部分：閱讀理解（共20小題，每題2分，滿分40分）

閱讀下列短文，從每題所給的四個(gè)選項(xiàng)（A、B、C和D）中，選出最佳選項(xiàng)，并在答題卡上將該項(xiàng)涂黑。

David Beckham had a dream: to be the first English player to appear in four World Cups.

But now it appears that dream is over after a serious injury to his Achilles tendon（跟腱）which means he could be out of action for around six months. With this year's World Cup in South Africa only three months away, sadly Beckham looks set to miss out.

The injury happened while Beckham was playing for AC Milan against AC Chievo in the Italian league. After attempting to kick the ball he collapsed to the ground and hobbled off the pitch before being stretchered（被擔(dān)架抬走）away.

It is not yet known whether he has completely severed（切斷）his Achilles tendon or only torn it. The player has now flown to Finland for assessment and treatment by a knee specialist.

England manager Fabio Capello fears the worst for Beckham's World Cup chances.

"We have to wait for the results of the scan but it looks like he is out of the World Cup," he said in a statement. "I spoke with him after the game on Sunday night to offer my support.

"David is a great professional and has worked very hard to be ready for the World Cup, so missing it will be a big blow."

Beckham's former manager at American club LA Galaxy, Alexei Lalas, echoed（共鳴）Capello's words of support:

"It is a horrible situation for Beckham. I know how much it meant to him to be in the World Cup and how important he was to the England team.

David Beckham is now 34 and some are asking whether this serious injury could mean his whole career is over.

Whatever happens, as one of football's best-known and popular players, Beckham will have no shortage of encouragement from fans around the world.

Some will remember Beckham's miraculous recovery from an Achilles injury in 2006, when he was back on the pitch after only eight weeks.

If he could repeat the same feat，in time for the World Cup it really would be the stuff of fairytales.

So, perhaps all is not lost. Optimists will take heart from Alexei Lalas' words:

"You never want to write off（排除）David Beckham as he has shown us his ability to bounce back（恢復(fù)原狀）."

56．What is the best title of the passage?

A．Beckham had a dream?

B．Beckham—a great football player!

C．The end for Beckham?

D．World Cup in South Africa!

57．What does the author mean by saying “missing it will be a big blow?”

A．Missing the World Cup will be a big success.

B．Missing Beckham means a great failure.

C．Missing Beckham means an important opportunity for the American club LA Galaxy.

D．Missing the World Cup means a big disappointment for Beckham.

58．We may infer from the passage that____________

A．Beckham will definitely not be able to play football again

B．Beckham was cured by a great knee specialist he found

C．Beckham has his ability to bounce back

D．Beckham is likely to miss the World Cup

59．What do the underlined words “take heart” probably mean?

A．get disappointed      B．get help    C．get encouraged D．get hurt

 

查看答案和解析>>

科目：高中英語 來源：全國通用2010屆高考英語考點(diǎn)預(yù)測：信息匹配 題型：信息匹配

 

The following people are expressing their thoughts (1--5) to show their concern for food, environment and so on．After that are pieces of related information (A--F) ．Now decide which piece of information would be most suitable for the thought and idea mentioned in questions61---5 and mark your answer letter (A---F) on your answer sheet．There is one extra paragraph which you do not need to use.

______1．How I was struck by the clear water and fresh air in my childhood! But everything has changed, that is, the clear water and fresh air are nowhere to be found again as they were． Above all, a great deal of waste hardly rots away.

______2．More and more people are beginning to have a good knowledge of the importance of a safer and cleaner environment, which in turn forces the business to be cleaned up.

______3．Organic products are getting more and more popular among people, but we should know the fact that organic products might also have something to do with pesticides.

______4．I`m very much fond of growing some vegetables of my own in my small garden, for many vegetables on sale in markets are actually becoming more and more dangerous as a result of widespread pesticides.

______5．Nowadays it is very convenient for consumers to find and buy green food in supermarkets as they are clearly marked.

         A．"Organic produce is always better, "Gold said．"The food is free of pesticides(農(nóng)藥) ,and you are generally supporting family farms instead of large farms．And more often than not it is locally grown and seasonal, so it is more tasty." Gold is one of a growing number of shoppers buying into the organic trend, and supermarkets across Britain are counting on more like him as they grow their organic food business.

         B．Market research shows that Gold and others who buy organic food can generally give clear reasons for their preferences - but their knowledge of organic food is far from complete．For example, small amounts of pesticides can be used on organic products．And about three quarters of organic food in Britain is not local but imported to meet growing demand．"The demand for organic food is increasing by about one third every year, so it is a very fast-growing market, "said Sue Flock, a specialist in this line of business.

         C．Many cities around the world today are heavily polluted．Careless methods of production and lack of consumer demand for environment-friendly products have contributed to the pollution problem．One result is that millions of tons of glass, paper, plastic, and metal containers are produced, and these are difficult to get rid of.

         D．However, today, more and more consumers are choosing "green" and demanding that the products they buy should be safe for the environment．Before they buy a product, they ask questions like these: "Will this shampoo damage the environment?"  "Can this metal container be reused or can it only be used once?"

         E．Only a few years ago, it was impossible to find green products in supermarkets, but now there are hundreds．Some supermarket products carry labels(標(biāo)簽) to show that the product is green．Some companies have made the manufacturing(制造) of clean and safe products their main selling point and emphasize it in their advertising.

         F．The concern for a safer and cleaner environment is making companies rethink how they do business．No longer will the public accept the old attitude of "Buy it, use it, throw it away, and forget it." The public pressure is on, and gradually business is cleaning up its act.

 

查看答案和解析>>

同步練習(xí)冊答案