classes so early in the morning. It may not be that the students who nod off at their desks are lazy. And
it may not be that their parents have failed to enforce (确保) bedtime. Instead, it may be that biologically
these sleepyhead students aren"t used to the early hour.
" Maybe these kids are being asked to rise at the wrong time for their bodies, " says Mary Carskadon,
a professor looking at problems of adolescent (青春期的) sleep at Brown"s School of Medicine.
Carskadon is trying to understand more about the effects of early school time in adolescents. And , at
a more basic level, she and her team are trying to learn more about how the biological changes of
adolescence affect sleep needs and patterns.
Carskadon says her work suggests that adolescents may need more sleep than they did at childhood ,
no less,as commonly thought.
Sleep patterns change during adolescence, as any parent of an adolescent can prove. Most
adolescents prefer to stay up later at night and sleep later in the morning. But it"s not just a matter of choice-their bodies are going through a change of sleep patterns.
All of this makes the transfer from middle school to high school-which may start one hour earlier in
the morning-all the more difficult , Carskadon says. With their increased need for sleep and their
biological clocks set on the "sleep late , rise late" pattern, adolescents are up against difficulties when it
comes to trying to be up by 5 0r 6 a. m. for a 7 : 30 a. m. first bell. A short sleep on a desktop may be
their bodies" way of saying,"l need a timeout. "
B. it is biologically difficult for students to rise early
C. students work so late at night that they can"t get up early
D. students are so lazy that they don"t like to go to school early
A. turn around
B. agree with others
C. fall asleep
D. refuse to work
B. Adolescents have to choose their sleep patterns.
C. Adolescents sleep better than they did at childhood.
D. Adolescents need more sleep than they used to.
B. Problems in adolescent learning.
C. Adolescent sleep difficulties.
D. Changes in adolescent sleep needs and patterns.
reward was certainly incomparable to the little effort that he had to put it. It began when he was selected
to help the teachers in the computer laboratories.
The peak of his school career came not when he topped the school but when he was selected for the
nationwide competition.Unlike everyone else, Nigel wanted to join the contest because he liked playing
with the Lego sets and making something out of them. Nigel spent the next two months rebuilding the
robot. It was during the time that Nigel found out about the prizes for the competition as well as another
competitor, Alicia, from a neighboring school. His early intentions were forgotten. Getting the
thousand-dollar prize was more important than anything else. Nigel decided to befriend Alicia.Unaware
of his intentions, she told him all about the robot that she had been building for the competition. He even
helped her to put the finishing touches to her robot. He was glad with the way things had progressed. His
robot looked even better than Alicia"s and it was able to bounce a ball with its arm , something Alicia
had failed to do.
On the day of the competition, he saw Alicia. Everything dawned on her the minute she saw him
among the competition. She stared at him, puzzled at rirst, then angry and finally a look of helplessness
came over her.
The flashbulbs of the camera exploded in Nigel"s face. The robot had performed actions so unique
and different that the specialists" judgments were the same. Nigel was so personal with himself that he
did not even notice the girl standing a few feet away from him. Without her,he would never have won the
competition.
B. He was honored with a scholarship.
C. He helped his teachers construct a robot.
D. He helped in the computer laboratories.
B. being great honor to his school
C. construct a robot with the Lego sets
D. win the thousand-dollar prize
B. He was fond of building robots.
C. He intended to help her.
D. He didn"t want her to suspect him.
B. He is strongly critical.
C. He is in favor of them.
D. His attitude is not clear.
direct experience,by testing and piroving an idea,or by reasoning.
We achieve knowledge passively by being told by someoneelse. Most of the learning that
takes place in the classroom and thekind that happens when we watch TV or read newspapers
ormagazines is passive. Conditioned as we are to passive leaning,it"snot surprising that we
depend on it in our everyday communication with friends and co-workers.
Unfortunately,passive learning has a serious problem. It makes us tend to accept what we
are told even when it is little more than hear say and rumor(谣言).
Did you ever play the game Rumor? It begins when one personwrites down a message but
doesn" t show it to anyone. Then the person whispers it,word for word, to another person.That
person,inturn,whispers it to still another, and so on, through all the peopleplaying the game. The
last person writes down the message word forword as he or she hears it. Then the two written
statements arec ompared. Typically, the original message has changed.
That" s what happens in daily life. The simple fact that peoplerepeat a story in their own words
changes the story.Then,too,most people listen imperfectly. And many enjoy adding their own
creativetouch to a story,trying to improve on it,stamping(打上标记)it with their own personal
style. Yet those who hear it think they know.
This process is also found among scholars and authors:Astatement of opinion by one writer
may be re-stated as fact by another,who may in turn be quoted by yet another;and this process
may continue,unless it occurs to someone to question the facts onwhich the origihal writer based
his opinion or to challenge the interpretation he placed upon those facts.
B. solving a math problem
C.visiting an exhibition
D.doing scientific reasoning
B. knowledge
C. communication
D. passive learning
B. a message should be delivered in different ways
C. people may have problems with their sense of hearing
D. people tend not to believe in what they know as rumor
B. Passive learning may not be reliable.
C. Active learning occurs more frequently.
D. Passive learning is not found among scholars.
A new study has found no evidence that sunscreen, commonly used to reduce the
risk of skin cancer, actually increases the risk.
Researchers from the Umversity of Iowa based their findings on a revicw of 18 earlier
studies that looked at the association between sunscreen use and melanoma(黑素瘤 ).
They said that they found flaws in studies that had reported associations between sunscreen
use and higher risk of melanoma.
Most health experts believe that by protecting the skin from the harmful effects of
the sun, sunscreen helps prevent skin cancer, which is increasing in incidence (发生率)
faster than any other cancer in the United States.
But questions have been raised about sunscreen and whether it may have the opposite
effect, perhaps by allowing people to remain exposed to the sun longer without burning.
The researchers said that among the problems with some earlier studies is that they
often failed to take into account that those people most at risk for skin cancer-people
with fair skin and freckles(雀斑) ,for example-are more likely to use sunscreen. As a
result , it may appear that sunscreen users get cancer more often.
The studies , which generally relied on volunteers to recall their sunscreen use,were
also unable to prove how well the products had been applied , Said the new study.
B. facts
C. faults
D. failures
B. are more in danger of skin cancer
C. can be free from the harm of the sun
D. often expose themselves to the sun
B. the volunteers have proved the effect of sunscreen
C. the new study was based on the experiences of volunteers
D. the number of skin cancer patients is increasing in America
B. Sunscreen to Increase Skin Cancer
C. Skin Cancer Caused by Sunscreen
D. Skin Cancer Caused by Freckles
注意:每个空格只填1个单词.
suggests. The results of the study added to the growing body of evidence that Rapid Eye Movement (REM) sleep is very important to the brain"s ability to form strong memories.
An average night"s rest includes four or five spells of REM sleep, but these bursts tend to be lengthier towards the end of the night. This means adults getting less than the recommended seven to eight hours a night -- and therefore inadequate REM sleep -- may be damaging their mind"s ability to memorize: Although REM sleep is not classified as a type of deep sleep, it is only reached after the brain has passed through deep
sleep stages.
In the recent study, participants were shown groups of three words and asked to find another word that can be associated with all three words. They were tested once in the morning and then given the same task
again in the afternoon. In between, some were allowed a nap with REM sleep, some a nap without REM
sleep, while the others had a quiet rest period. The quiet rest and non-REM sleep groups didn"t improve, but the REM sleep group improved on their morning performance by an average of almost 40 per cent. Dr Sara Mednick, a sleep researcher at the University of California who led the study, believes the formation of
connections between previously unassociated information in the brain occurs during REM sleep.
It is believed that sleep acts as a sort of mental filing system, enabling the brain to sort relevant
information from useless information. This process may take place as memories are removed hem one art of the brain to others.
Title | REM Sleep (1) ______ Memory |
The result of the study | Rapid Eye Movement sleep is of great importance to the brain"s ability to (2) ______ memories. |
The (3) ____ of the study | ◆ (4) ______ were required to think of another word associated with all three words. ◆The same task was given to participants (5) ______ a day. ◆ The quiet rest and non-REM sleep groups showed no (6) ______. ◆ The REM sleep group (7) ______ well by an average of almost 40 per cent. |
Dr Sara Mednick"s (8)_____ | Connections between previous unassociated information in the brain are (9) ______ during REM sleep |
Conclusion | Sleep acts as a sort of mental filing system, enabling the brain to abandon useless information and keep the (10) ______ information. |
阅读理解 | |
A recent study conducted by researchers at the University of Michigan " s Center for Human Growth and Development shows that children aged 9 t0 12 who sleep less than nine hours a night can have real problems with gaining weight. Dr.Julie Lumeng, lead author of the report said, " Many children aren"t getting enough sleep , which may not only make them annoyed or prevent them from being active and ready to learn at school,but also lead to a higher risk of being overweight. " Reuters reports. She also said that children who sleep more than 10 hours a night are more willing to play and consume their energy , rather than staying in bed or watching TV as their tired fellows do. It is also said that hormonal(荷尔蒙) changes brought on by a lack of sleep can lead to an increased appetite. The study focused on 785 children aged 9 to 12 from 10 different states and it confirmed that 18% were overweight by the time they reached the sixth grade. Children who do not sleep nine or more hours a night when they are in the third grade are more likely to gain weight by the time they are in the sixth grade. The conclusion of the study is very simple : "Our findings also provide additional support for policies that approve of later school start times. The very early school start times for US children have raised concerns in the medical community because of their apparent negative effects on sleep duration(廷续性) and , consequently, children"s general academic and behavioral functioning , " Reuters reports. According to National Sleep Foundation, children in first grade should sleep from 10 to 12 hours a night. Dr. Julie Lumeng" s report was published in the journal of the American Academy of Pediatrics (小 儿辩 ) in November. | |
1. According to Dr. Julie Lumeng, if children lack sleep, they _____. | |
A. fall asleep during the lecture B. become unhappy and inactive C. are ready to leam their lessons D. are active in doing school work | |
2. Children who get enough sleep seem more active because_____. | |
A. they experience a pleasant time B. they are better at playing sports C. they have enough energy to use D. their personalities are more outgoing | |
3. What does the author want to argue in Paragraph 5? | |
A. Students in the third grade are more likely to gain weight. B. A lack of sleep is associated with weight gain. C. Less than one fifth of children are overweight. D. The longer they sleep , the heavier they become. | |
4. Why has medical community showed concerns about US children ? | |
A. Because US children traditionally get up very late. B. Because many students complain of too long school hours. C. Because later school start times may affect children physically. D. Because a lack of sleep creates harmful effects on children. | |
5. What is the best title for the text? | |
A. Lack of Sleep Leads to Childhood Overweight B. A Recent Study on Health Problem C. A Danger to Children"s Health D. Sleep Time and Overweight |