Teenagers who check social media for several hours a day are at the risk of developing ADHD （多動(dòng)癥），a study has concluded.
The research team，from the University of Southern California，tracked 2，600 teenagers aged 15 and 16.They asked them how many times they checked their phones and other digital devices for various reasons，and then monitored them for symptoms of ADHD.After two years，those who had checked their phones the most often were twice as likely as those who checked the least often to show signs of ADHD.
Writing in the JAMA medical journal，the scientists said， "Modern media devices immediately inform users when new text messages，social media postings，or videogame play invitations arrive.Exposure to such information may draw attention away from important tasks.Frequent distraction could interrupt the development of constant attention and organization skills."
They believe constant access to instant entertainment also has an impact.Researcher Professor Adam Leventhal said all previous research had focused on the link between ADHD and televisions. "What's new is that previous studies on this topic were done many years ago，when social media，mobile phones，tablets and mobile apps didn't exist.We can say with confidence that teens who are exposed to higher levels of digital media are significantly more likely to develop ADHD symptoms in the future，" he said.
Leventhal believes the findings help fill a gap in understanding how new mobile media devices and seemingly limitless content pose a mental health risk for children.And the findings serve as a warning.
British scientists welcomed the findings.But Professor Andy Przybylski of the Oxford Internet Institute said， "The study relies on survey responses provided by the students in question.It is not clear if teachers or parents would rate the children similarly or if the self-reported measure of digital screen use is related with either actual behavior or higher quality survey items."
（1）How did the researchers conduct the study？ BB
A．By monitoring 2，600 teenagers with ADHD.
B．By tracking the participants for two years.
C．By analyzing data from previous researches online.
D．By controlling different teens' time spent on social media.
（2）What does Leventhal think of the exposure to higher levels of digital media？ BB
A．It will cause diverse ADHD symptoms.
B．It will create higher ADHD risks.
C．It will weaken teenagers' confidence.
D．It will have a major influence on organization skills.
（3）What does Professor Andy Przybylski think of the study？ CC
A．It provides a better understanding of the media.
B．It should have focused on parents' responses.
C．Its findings are not reliable enough.
D．It's a breakthrough in this field.
（4）What can be a suitable title for the text？ CC
A．The use of digital media is on the rise
B．Teens are increasingly exposed to ADHD
C．Heavy use of social media may increase ADHD risks
D．Teens' exposure to modern media calls more attention
【答案】B；B；C；C
【解答】
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發(fā)布：2024/4/20 14:35:0組卷：3引用：3難度：0.7
相似題
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1．Rainforests provide much of the world's oxygen.People have been trying to protect them for years.But another type of forest，the cloud forest，is just as important to humans.
These forests are at the tops of mountains，generally near the equator （赤道）.These wet，wooded mountaintops are mainly in African and Central and South American countries.They are called "cloud forests" because their height allows for the formation of clouds among the trees.The trees in these forests pull water out of the clouds.The water gathers on the leaves and falls into small rivers below，which flow into towns at the bottom of the mountain.The yearly rainfall in these areas is about 180 centimetres.Cloud forests can pull in up to 60 percent of that.The water is important to the plants and the people in the area.It helps them survive.
Cloud forests are also home to countless species of plants that can't be found anywhere else.One small cloud forest has as many types of plants as there are in all of Europe.In fact，there are so many that scientists haven't made a complete list of them yet.
These forests are being destroyed at increasing speed.Trees are being cut down，and roads are being built in their place.Some people have a goal to get government money to protect the forests.But they have had little success so far.Another way is to take the place of the destroyed plants with new ones.That，too，has been difficult because the plants are so special.There's plenty of work to be done，but saving the cloud forests is still possible with creative solutions.
（1）Where can you probably find cloud forests？
A．In North America.
B．Far from the equator.
C．In an African country.
D．At the foot of mountains.
（2）How much rainfall is pulled in by the cloud forests in those areas every year？
A．About 60 cm.
B．About 108 cm.
C．About 180 cm.
D．About 300 cm.
（3）What is the main idea of paragraph 3？
A．Europe is short of plant types.
B．Scientists are working on a list.
C．Cloud forests are getting smaller.
D．Cloud forests house many plants.
（4）What will be discussed in the following part of the text？
A．Ways to protect cloud forests.
B．Goals of cloud forest protectors.
C．Difficulties in planting new trees.
D．Successes of getting wide support.
（5）Where can we probably find the text？
A．In a storybook.
B．In a travel guide.
C．In a chemistry textbook.
D．In a geography magazine.發(fā)布：2025/1/1 18:0:1組卷：7引用：3難度：0.5 -
2．The baby is just one day old and has not yet left hospital．She is quiet but alert（警覺(jué)）．Twenty centimeters from her face researchers have placed a white card with two black spots on it．She stares at it carefully．A researcher removes the card and replaces it by another，this time with the spots differently spaced．As the cards change from one to the other，her gaze（凝視） starts to lose its focus - until a third，with three black spots，is presented．Her gaze returns；she looks at it for twice as long as she did at the previous card．Can she tell that the number two is different from three，just 24 hours after coming into the world？
Or do newborns simply prefer more to fewer？The same experiment，but with three spots shown before two，shows the same return of interest when the number of spots changes．Perhaps it is just the newness？When slightly older babies were shown cards with pictures of objects（a comb，a key，an orange and so on），changing the number of objects had an effect separate from changing the objects themselves．Could it be the pattern that two things make，as opposed to three？No again．Babies paid more attention to squares moving randomly on a screen when their number changed from two to three，or three to two．The effect even crosses between senses．Babies who were repeatedly shown two spots became more excited when they then heard three drumbeats than when they heard just two；likewise（同樣地） when the researchers started with drumbeats and moved to spots．
（1）The experiment described in Paragraph 1 is related to the baby's．
A．sense of hearing
B．sense of sight
C．sense of touch
D．sense of smell
（2）Babies are sensitive to the change in．
A．the size of cards
B．the colour of pictures
C．the shape of patterns
D．the number of objects
（3）Why did the researchers test the babies with drumbeats？
A．To reduce the difficulty of the experiment．
B．To see how babies recognize sounds．
C．To carry their experiment further．
D．To keep the babies' interest．
（4）Where does this text probably come from？
A．Science fiction．
B．Children's literature．
C．An advertisement．
D．A science report．發(fā)布：2025/1/1 17:0:1組卷：3引用：4難度：0.5 -
3．Photo Research "If you want to be a better photographer，stand in front of better stuff." Photographer Jim Richardson shared it with otjye.airs.He spends a great deal of time doing photo research，looking for great locations to shoot.
Seeing a wonderful place is bread-and-butter photography-it's just part of the job.Getting there is only half of any great photograph's story.The other half is how the photographer prepares to capture the subject once in front of jye.ai.It is believed that groundwork is part of photography，as essential as knowing exposure and lighting or recognizing the decisive moment to take the shot.Research sounds like a boring task for many photographers，while for others digging into a subject in advance is part of the pleasure.
Philosophically，photographers seem to divide along that line.On one side are those who desire only to be in the moment.On the other side are the planners.They would never dream of going out the door without a full list of how they're going to approach the shoot.Actually，there is a third group nowadays.They just take photos of the whole scene and do all the creative work in Photoshop after the event.Most photographers do both：research carefully to prepare their schedule and then act in the moment once on site.
Photographers should do a lot of research in order to get ready for a photographic trip.This includes creating a file for each location they are due to visit.They start a file for each place and begin to make a list of the pieces of information.Knowing what the place looks like in advance is invaluable，so it is good to hit several Internet photo sites.Besides clueing them into the photographic possibilities of the location，this can also show what angles have already become overused and which they should therefore avoid.But photographers will also find angles they didn't expect from locations they hadn't imagined.Armed with these they will be better prepared to push the boundaries of what they expect.
"Above all，I'll look for places and events that are seasonal and timeless.I open my mind to what might make a great subject for a picture，" Jim said. "Most travelers tend to think only of places they're visiting，without looking deeper into culture，history or meaning.I try to get in time with the rhythm of the place and in tune with its melody.But most of all I just want to be ready.If I'm ready，I can just about count on being lucky."
（1）What does the underlined word "capture" in Paragraph 2 probably mean？
A．Identify.
B．Record.
C．Arrange.
D．Explore.
（2）What point does the author make about photographers in Paragraph 3？
A．They are unable to decide on the best plan of action.
B．It is possible for them to adopt flexible ways of working.
C．The third group is not as imaginative as some of the others.
D．Some of them refuse to try to understand the way others work.
（3）What is the main idea of Paragraph 4？
A．Sound preparation is a must for a satisfactory photo.
B．One should create photo sites in a photographic trip.
C．Taking photos requires vivid imagination in advance.
D．It is essential to do photo research in central locations.
（4）In the last paragraph，Jim states that.
A．he feels good to visit those historical places
B．he refuses to spend too much time in one place
C．he is careful about choosing the right place to visit
D．he likes to go to places that few people bother to visit發(fā)布：2025/1/1 18:0:1組卷：20引用：3難度：0.7