题目内容

B vitamins(维生素)may offer some protection against the effect of air pollution,a new study suggests.

The scientists say the effect is real but stress the limitations of their work.Follow-up studies are urgently needed, they say,in heavily polluted cities like Mexico.

According to the World Health Organization (WHO),over 90% of the world's population live in heavily-polluted areas.The one of the pollutants that is considered the most dangerous is very fine particulate matter, referred to as PM2.5.At around 1/30 the width of a human hair,PM2.5 can go deep into the human lung and contribute to lung and heart health problems in the young and old.

Scientists have long suspected that PM2.5 causes what are termed epigenetic(表观遗传)changes in our cells that can damage our health.Now in this new human trial,an international team of scientists wanted to see if exposure to concentrations of PM2.5 could be mitigated by daily B vitamins.

Ten volunteers were tested initially exposed to clean air and their basic responses were measured.The same volunteers were later tested with large doses(剂量)of B vitamins while exposed to air containing high levels of PM2.5.The researchers found that a four-week B vitamin intake limited the PM2.5 effect by between 28-76% at ten gene locations.They found a similar reduction in effect on the mitochondrial DNA,the parts of cells that produce energy.

However,the researchers caution that their study,while observing a real effect,has limitations.As well as the small number of participants,there was little information on the size of the B vitamin dose that caused the response.

1.What is the main idea of the text?

A. B vitamins may fight against PM2.5.

B. PM2.5 can lead to epigenetic changes.

C. Further studies should be done on PM2.5.

D. Exposure to PM2.5 is more and more serious.

2.Which can replace the underlined word "mitigated" in Paragraph 4?

A. measured B. ignored

C. reduced D. observed

3.How many limitations does the text mention about the new study?

A. 2. B. 3.

C. 4. D. 5.

4.How does the writer of the text like the new study?

A. He believes it deeply. B. He criticizes it strongly.

C. He thinks it needs testing again. D. He shows no opinion about it.

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9.In science,people copy ideas from nature or natural processes to solve problems or to create products which will serve a specific purpose to help us.This is called biomimicry and its influence can be seen in many everyday products.
We are all familiar with Velcro(魔术贴).It was invented in 1941by a Swiss engineer called George de Medtral,who found some seeds stuck to his dog's hair.Under the microscope,he discovered that these seeds had hooks(钩) on them,so they could easily stick to clothing or hair.He copied this idea and invented Velcro.It was initially unpopular with fashion companies but after it was used by NASA(美国国家航空航天局)to stop items floating in space,it became popular with children'clothing companies.
More recently,swimwear has also been influenced by nature.The Speed to Fastskin,a controversial swimsuit,was seen at the Beijing Olympics and worn by 28of the 33gold medal winners.The technology is based on the rough patterns on a shark's skin,which allows the shark to swim faster.Shark skin also stop bacteria growing on it,so scientists are copying this surface to design cleaner hospitals.
For NASA,protecting astronauts'eyes from the sun's rays and other dangerous radiation is very important.Scients studied how eagles see things clearly.They discovered that a substance called yellow oil in their eyes does the trick.NASA copied this oil and it is now used by astronauts and pilots in Eagle Eyeglasses.In addition to protecting eyes from all the dangerous rays,these sunglasses also help people see more clearly in even poor weather conditions such as fog.
It appears that influence of biomimicry is unlimited,so it will be interesting to see what solutions nature provides us with in the future.
28.George de Mestral invented VelcroC.
A.to challenge fashion companies       
 B.after he studied his dog's hair
C.after he examined some seeds         
D.to satisfy NASA's demand
29.At the Beijing Olympics,the Speedo Fastskin swimsuitA.
A.helped swimmers perform better        
B.was recommended by champions
C.received widespread approval          
D.made swimmers healthier
30.What make eagles see clearly?D
A.The size of their eyes                 
B.The shape of their eyes
C.The colour of their eyes               
D.The substance of their eyes
31.What's the best title for the text?B
A.The future of biomimicry              
B.The magic of biomimicry
C.The purpose of biomimicry             
D.The limitation of biomimicry.
9.Music is magic!Music speaks louder than words and it is a"language"that the whole world can understand.A piece of music can produce a response in the heart and mind.Like feeling an electrical current or receiving a personal radio signal,music has a spiritual effect on a person.Different kinds of music influence people in different ways.
I have listened to music all my life.When I was twelve years old,the Beatles came to America and my whole world opened up.Maybe young people today cannot understand the influence of the Beatles when they exploded across America.Their influence changed the way we dressed,looked,acted and spoke even our culture.The Beatles arrived in America from the UK just under three months after the assassination(暗杀)of President John Kennedy,which had put America into a great depression.And the freshness and lively sprit of the Beatles was exactly what the country needed to refresh itself.
Music links the heart of the hearer with that of the composer.This means that it mixes the spirit of the composer with your spirit when you listen to it.And the music can take your spirit out of your body and transport you into another world.Music has a great way of touching people.Music can make you laugh,cry or shout.It's also a great source of inspiration.
Try this one day and notice what happens:make yourself a cup of tea,sit on your sofa and play one of your favorite songs.Close your eyes,and soon you'll find yourself creating vivid mental images---matching the music that you are listening to.

28.Music has magical power because itD.
A.is a kind of language
B.can be played much louder than words
C.receives a personal radio signal
D.can influence a person's spirit
29.One can learn from the second paragraph that the BeatlesC.
A.were the biggest band in American history
B.are not accepted by modern American people
C.appeared at a special time in American politics
D.represented the roots of American culture
30.One will do all of the following while listening to music EXCEPTC.
A.feeling very refreshed
B.having emotional changes
C.painting some vivid pictures
D.feeling inspired by the composer
31.It can be inferred from the passage that the authorA.
A.has been influenced by the Beatles
B.enjoys drinking tea in his spare time
C.admires President John Kennedy very much
D.likes to match his own feeling with that of the composer.

I was never very neat, while my roommate Kate was extremely organized. Each of her objects had its place, but mine always hid somewhere. She even labeled(贴标签) everything. I always looked for everything. Over time, Kate got neater and I got messier. She would push my dirty clothing over, and I would lay my books on her tidy desk. We both got tired of each other.

War broke out one evening. Kate came into the room. Soon, I heard her screaming, ‘Take your shoes away! Why under my bed!’ Deafened, I saw my shoes flying at me. I jumped to my feet and started yelling. She yelled back louder.

The room was filled with anger. We could not have stayed together for a single minute but for a phone call. Kate answered it. From her end of the conversation, I could tell right away her grandma was seriously ill. When she hung up, she quickly crawled(爬) under her covers, sobbing. Obviously, that was something she should not go through alone. All of a sudden, a warm feeling of sympathy rose up in my heart.

Slowly, I collected the pencils, took back the books, made my bed, cleaned the socks and swept the floor, even on her side. I got so into my work that I even didn’t notice Kate had sat up. She was watching, her tears dried and her expression one of disbelief. Then, she reached out her hands to grasp mine. I looked up into her eyes. She smiled at me, ‘Thanks.’

Kate and I stayed roommates for the rest of the year. We didn’t always agree, but we learned the key to living together: giving in, cleaning up and holding on.

1.What made Kate angry one evening?

A. She couldn’t find her books

B. She got the news that her grandma was ill

C. She heard the author shouting loud

D. She saw the author’s shoes beneath her bed

2.The author tidied up the room most probably because .

A. she was scared by Kate’s anger

B. she wanted to show her care

C. she hated herself for being so messy

D. she was asked by Kate to do so

3.How is Paragraph 1 mainly developed?

A. By analyzing causes B. By describing a process

C. By showing differences D. By following time order

4.What might be the best title for the story?

A. My Friend Kate B. Hard Work Pays Off

C. How to Be Organized D. Learning to Be Roommates

7.Mr.White is talking to a psychiatrist.Mr.White:"Every night when I get into bed,I think that someone is under my bed.then I get up and look.There is never anyone there.When I go under the bed and lie down,I get the idea that there is someone on top of the bed.I then get up and look and I never find anyone on top of the bed.This goes on all night,up and down,up and down.I nearly get mad.Do you think you can help?"
Psychiatrist:"I think I can.All you have to do is to visit me twice a week for the next two years and I think I can cure(治愈)you.The visits will costs$75an hour."
Mr.White:"That is an awful lot of money for a working man like me.I'll have to talk it over with my wife and let you know."
The next week Mr.White phoned the Psychiatrist.
Mr.White:"I won't be back,sir.My wife solved the problem.She cut the legs off the bed."
26.Mr.white isA
A.ill in mind(精神) 
B.crazy about sports
C.interested in his bed  
D.afraid of someone in his house
27.The psychiatrist works as aC
A.teacher   
B.volunteer   
C.doctor    
D.listene
28.The psychiatrist told Mr.White toB
A.ask his wife for help     
B.visit him a lot more
C.cut the legs off the bed   
D.believe his abilities
29.Mr.White became all right with the help ofB
A.the psychiatrist   
B.his wife    
C.his bed     
D.a working man
30.Which of the following statements is TRUE?C
A.Mr.White is in a good health because he exercises every day.
B.The psychiatrist made a lot of money by helping Mr.White.
C.Mr.White has a smart wife who is very helpful
D.Mr.White went mad after he  went to see the psychiatrist.

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