For many of us, a little time with our smartphones or iPads before sleep is the highlight of the night. But would you still think it is relaxing if you knew that it damages or destroys your sleep? Scientists say that's exactly what it does.
In ancient times, when there were no lamps, telephones or smartphones, the sun was the main source of light. When the sun went down, our brains took that as a signal to start producing melatonin(褪黑素), a chemical that helps us sleep.
However, a healthy amount of melatonin can only be produced in complete darkness.Any light in your bedroom—even the one on the alarm clock or the charging indicator on your cellphone—could disturb the process, not to mention something as bright as smartphone and iPad screens. We tend to hold these much closer than a television or laptop, which allows them to shoot far more light straight into our eyes.
“This is particularly worrisome in populations such as young adults and adolescents, who already tend to be night_owls，” said researcher Brittany Wood at Rensselaer Polytechnic Institute.“Lack of sleep among teens is leading to depression, self­harm, low concentration and poor performance at school，” she added.
While all lights are the enemy of sleep, not all colors of light have the same effect. Our eyes are particularly sensitive to blue light, which is common during the day. Most of the light coming from electronic screens is blue light and it fools our brain into thinking it's still daytime. By contrast, orange or red light has less influence on melatonin production, because our brains recognize it as a signal that the day is ending, according to The Telegraph.
Asking yourself to keep your hands off your smartphone before bedtime might seem unreasonable, but you should at least remember to dim the screen or hold it farther away from your eyes. You could also wear a pair of orange sunglasses that take away the harmful blue light.
小題1:According to the passage, we can know ________.
A．it's a good habit to play with smartphones or iPads late into night
B．scientists suggest we should avoid using smartphones or iPads
C．darkness makes a great impact on the amount of melatonin
D．the sun was the only source of light in ancient times
小題2:Which of the following is TRUE according to the passage?
A．The darker it is, the more melatonin will be produced.
B．The lighter it is, the more melatonin will be produced.
C．The more melatonin you have, the worse you'll sleep.
D．The more electrical equipment you have, the more melatonin will be produced.
小題3:The underlined part in Paragraph 4 refers to those ________.
A．who are young adults or adolescents
B．who don't perform well in school
C．who are addicted to a television or laptop
D．who are short of sleep at night and perform poorly in daily life
小題4:In the writer's opinion, which is a correct suggestion?
A．You should go to bed when the sun goes down.
B．You should use an orange or red light electronic screen.
C．You should wear a pair of blue sunglasses when sleeping.
D．You should avoid blue light as possible as you can before bedtime.

小題1:C
小題2:A
小題3:D
小題4:D
本文是一篇科技說明文。研究發(fā)現(xiàn)，睡前玩手機(jī)可能會影響睡眠狀況。
小題1:答案：C　推理判斷題。根據(jù)第二段最后一句及第三段第一句可知，C項(xiàng)正確；根據(jù)第一段內(nèi)容可知，A項(xiàng)錯誤；根據(jù)文章內(nèi)容可知，科學(xué)家們只是建議睡前不要玩手機(jī)，故B項(xiàng)錯誤；根據(jù)第二段中的“In ancient times，when there were no lamps，telephones or smartphones，the sun was the main source of light.”可知D項(xiàng)為錯誤結(jié)論。
小題2:答案：A　推理判斷題。根據(jù)第二段中的“our brains...a chemical that helps us sleep”及第三段首句“However，a healthy amount of melatonin can only be produced in complete darkness.”可知A項(xiàng)正確并排除B、C兩項(xiàng)。根據(jù)第三段中的“even the one on the alarm clock or the charging indicator on your cellphone—could disturb the process，not to mention something as bright as smartphone and iPad screens.”可排除D項(xiàng)。
小題3:答案：D　推理判斷題。根據(jù)第四段內(nèi)容尤其是最后一句可知，night owls指的就是晚上熬到很晚，缺乏睡眠，然后白天不能集中精神，表現(xiàn)不好的那些人。故D項(xiàng)正確。
小題4:答案：D　細(xì)節(jié)理解題。根據(jù)倒數(shù)第二段內(nèi)容可知，并不是所有顏色的光都會產(chǎn)生同樣的作用。我們的眼睛對藍(lán)色的光尤為敏感，它會傳遞給我們的大腦錯誤的信息，讓大腦以為還在白天，因此會影響我們的睡眠，所以在睡覺前應(yīng)避免接觸藍(lán)光。D項(xiàng)正確。
練習(xí)冊系列答案
相關(guān)習(xí)題

科目：高中英語 來源：不詳 題型：閱讀理解

A job is more than just a job，especially to the older generation.“It’s not the money that matters，but the sense of self­worth，” 56­year­old Cheng Wonlan said.So，every day Ms Cheng carries a bag of parcels，letters and documents of all shapes and sizes and does her rounds in North Point.She’s a courier(快遞人員)．
Five years ago，Ms Cheng was a nurse at a private clinic.She had worked there for almost 30 years but was made jobless when the doctor migrated(移居)．It was extremely difficult for her to find another job.“People do not trust my ability when they learn how old I am，” she said.After two years of searching，the mother of two eventually found another nursing job.But then after two years，she quit.Why?
“My colleagues were young and they didn’t understand me because of my age.They often asked me，‘You are so old；what are you working for？’ I was very unhappy.” she said.So while the rest of her family left for work，she was left to lonely boredom at home.The urge to work drove her to suffering.Then，one of Ms Cheng’s neighbours told her about Employee’s Retraining Board (ERB) offering retraining courses for older people on specific occupations，such as convenience store assistants，junior clerks and so on.
“I was interested in courier work.I didn’t think my age was a barrier because I was fit and healthy.So I thought why not give it a try.” she said.Upon graduation from the ERB，Ms Cheng was offered a job by the Speeding Shuttle Courier Service Company Limited.But then Ms Cheng was faced with a conflict：she was caught between honour and employment.It took Ms Cheng 24 hours to make up her mind and eventually came to the conclusion that there was nothing wrong or embarrassing about doing the job.So she took heart and went off to work as a courier.
Ms Cheng’s employer is delighted with her，“Ms Cheng has been working with us for two months and has shown a good responsible attitude to work.”Anthony Chong，who runs the company，said.Currently，Mr Chong has 60 couriers working for his company：five of them are over fifty，four of whom have been through the ERB plan.Mr Chong said he hired older people because they were able and reliable.“Age is not an important factor but attitude is.Many old people are more capable than the youngsters.They will not run from difficulties but the young ones will，” he said.“It is not easy to recruit (招募) young people since they shy away from hardship and challenges.”
小題1:Why was it difficult for Ms Cheng to find another nursing job?
A．Nursing clinics were hard to find.
B．People thought that old people couldn’t be trusted.
C．People thought she was too old to take on a new job.
D．People didn’t think she had enough working experience.
小題2:Ms Cheng left her second nursing job because ________.
A．she was bored
B．it was too difficult
C．she was too old to do the job
D．the other staff made her feel uncomfortable
小題3:Employee’s Retraining Board is a plan for ________.
A．finding jobs for older people
B．teaching new skills to older people
C．training older people to be couriers
D．giving older people something to do in their spare time
小題4:When Ms Cheng was offered the courier job she ________.
A．took it straight away
B．thought it over and then accepted it
C．thought about it and then refused it
D．refused it straight away but then changed her mind

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

Although similar in appearance to hyenas(土狼), African wild dogs are nevertheless true wild canine(犬). They are a mixture of black, yellow, and white in such a wide variety of patterns that no two individuals look exactly alike. African wild dogs are widely distributed across the African plains but they do not live in jungle areas.
They are social animals, living in groups of usually from 2 to 45 individuals. A hierarchy（統(tǒng)團(tuán)） exists within the group,  but the animals are friendly to one another. The young and the infirm（體弱的） are given special privileges within the group.
African wild dogs use their sense of sight, not smell, to find their prey. They can run up to 55 km/h for several kilometers. In eastern Africa, they mostly hunt Thomson's gazelles, but they will also attack calves, warthogs, zebras, impalas, and the young of large antelopes such as the gnu.
Growing human populations have decreased or degraded the African wild dog's habitat and also diminished their available prey. Road kill and human persecution（迫害） have also had a negative impact on African wild dog populations. This species is also susceptible to a variety of diseases such as distemper, which is controlled in domestic .dogs. Conservation of the African wild dog's natural habitat must have the highest priority, as these dogs suffer in habitats modified by human intrusion（干擾）．
小題1:What does the underlined word "susceptible" mean?
A．easily affected or sufferedB．badly doubtful
C．seriously harmful D．highly dangerous
小題2:What factors affect the population of the wild dogs?
a. the distribution of the dogs                  b. social living
c. highly increasing human populations          d. human's killing the dogs
e. many diseases                           f. the changes of their habitats
g. domestic dogs                            h. food reduction
A．a(chǎn). b, c, d, eB．b, c, d, e, fC．c, d, e, f, hD．d, e, f, g, h
小題3:From the passage we can conclude that_______.
A．African wild dogs are completely different from domestic dogs in size, weight
B．African wild dogs are living in groups
C．African wild dogs use their eyes mostly when sleeping to guard
D．African wild dogs use their noses to find their food in most cases
小題4:What can we know about African wild dogs?
A．In a pack there may be about 90 wild dogs and no leader.
B．There are no such wild dogs that are different.
C．African wild dogs can run at a speed of about 15 m/s for a long distance.
D．All African wild dogs kill zebras, impalas, and antelopes as their food.
小題5: What can we infer from the passage?
A．African wild dogs are not in danger, because there are such a wide variety of patterns.
B．African wild dogs are not in danger, because are widely distributed across the African plains.
C．African wild dogs are in danger, because human's activities have a great effect on them.
D．African wild dogs are in danger, because their habitats have been changed much.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

According to the US Geological Survey, about seven million earthquakes strike worldwide every year—but fortunately, only about 1500 of these are of a magnitude(震級) of 5 or greater on the Richter scale. Certain areas, such as California and Japan, are more prone to earthquakes than others. Although the chance of being caught in “The Big one” is remote, it’s wise to be prepared if you live in a region where earthquakes are common.
Educate your family about earthquakes before a big one strikes. For example, they need to know to take shelter in a doorway or under a strong object if indoors, and never to run outdoors if they are inside. If outside, they need to know to stay away from power lines and buildings where objects could fall.
Teach family members how to turn off gas or water lines or electrical power that may need to be shut off after a quake if severe damage occurs.
Develop a plan. Where will your family meet in the event of a disaster? What if some people are at work or school? How will you know if they are safe? Where will you all meet up?
Pack a preparedness kit(衣物裝備) and keep it in a safe location. In a major earthquake, it’s possible that you won’t be able to get into your house. Keep supplies in your car trunk or an outside storage shed if possible. Pack whatever your family is likely to need, enough for three days to a week, including food, water, medication, first aid and personal hygiene supplies, flashlights, a portable radio, blankets, clothes and shoes, cash, or camp stove, candles, matches or lighters, and a whistle.
Consider earthquake insurance for your home if you live in an earthquake-prone area. Regular homeowner’s insurance doesn’t cover earthquake damage.
小題1:The underlined words “prone to ” in paragraph 1 can be replaced by___________.
A．likely to sufferB．frequent to explore
C．regular to measureD．impossible to experience
小題2:According to the passage, if you are outside in an earthquake, you should_________.
A．stay where you areB．hide under a big tree
C．a(chǎn)void power linesD．sit on the ground
小題3: We can learn from the passage that_________.
A．a(chǎn)bout 1,500 earthquakes happen every year
B．people should store some clothes in their houses in advance
C．family members should meet in their home after an earthquake
D．people suffering earthquakes often should buy earthquake insurance
小題4:What would be the best title for the passage?
A．How to Keep Safe in an Earthquake
B．How to Prepare for an Earthquake
C．Who Can Help Us After an Earthquake?
D．Where Is an Earthquake-prone Area?

查看答案和解析>>

科目：高中英語 來源：不詳 題型：完形填空

Many animals recognize their food because they see it. So do        . When you see an apple or a piece of chocolate you know that these are things you can eat. You can also use other         when you choose your food. You may         it because it smells good or because it         good. You may dislike some types of food because they do not look, smell or taste very nice.
Different         use different senses to find and choose their food. A few animals depend on only one of their senses, while most animals use more than one sense.
Although there are many         types of food, some animals spend their lives eating only one type. The giant panda eats only one         type of bamboo. Other animals eat only one type of food even when given the       . A kind of white butterfly will stay on the leaves of a cabbage, even though there are plenty of other        in the garden. However, most animals have a more         diet. The bear eats fruits and fish. The fox eats small animals, birds and fruits. The         of these animals will be different depending on the season.
       have a very varied diet. We often eat food because we like it and not because it is       for us. In countries such as France and Britain, people eat foods with too much        . This makes them overweight, which is bad for their health. Eating too much red meat and animal        , such as butter, can also be bad for the health. Choosing the right food, therefore, has become an area of study in modem life.
小題1:
A．malesB．childrenC．humansD．a(chǎn)dults
小題2:
A．organsB．sensesC．partsD．means
小題3:
A．hateB．sellC．likeD．fancy
小題4:
A．digestsB．consumesC．touchesD．tastes
小題5:
A．creaturesB．mammalsC．peopleD．a(chǎn)nimals
小題6:
A．differentB．rareC．familiarD．unique
小題7:
A．typicalB．particularC．specialD．unusual
小題8:
A．foodB．mealC．choiceD．diet
小題9:
A．flowersB．vegetablesC．fruitsD．branches
小題10:
A．variedB．creativeC．randomD．nutritious
小題11:
A．fishB．fruitC．dietD．insect
小題12:
A．AnimalsB．ChineseC．HumansD．Foreigners
小題13:
A．effectiveB．beneficialC．deliciousD．a(chǎn)ttractive
小題14:
A．sugarB．nicotineC．fiberD．a(chǎn)lcohol
小題15:
A．productsB．a(chǎn)ttachmentsC．goodsD．subscriptions

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

In the last couple of years, there has been a craze about time­traveling TV series in China.This year, it seems like the South Korean drama writers have fallen in a deep, neverending love with the time­travel trend.
Rooftop Prince
A prince from the Joseon era (18th century), Lee Gak is catapulted 300 years forward into the future in Seoul 2012 with his entourage(隨從) when he tries to investigate the suspicious circumstances which surround the death of the woman he loves.In the present, he finds a young woman who looks exactly like his beloved crown princess.
Queen In­hyun's Man
The drama, set during the Joseon era, features the hero Kim Boong­do as he tries to restore the exiled Queen In­hyun.It is in this time period he is given the time­traveling power that transports him to the future world where he makes friends with an actress playing the role of Queen In­hyun for a drama in her time.
Dr Jin
Jin Hyuk is a genius neurosurgeon.Through a mysterious power, Jin finds himself transported back in time 150 years.He begins treating people there, but the lack of equipment and medical knowledge of the period forces him to seek new ways to aid the sick.Through this challenging process, Jin eventually becomes a genuine doctor.
Operation Proposal
Kang Baek­ho realizes that he falls in love with his best friend, Ham Yi­seul, on the day of her wedding to another man.He travels back in time to various events of their lives hoping to change the outcome of their relationship.Will Kang be able to change the course of their future?
小題1:Which of the following words can replace “catapulted” in Paragraph 2?
A．Captured.B．Transported.
C．Traveled.D．Deserted.
小題2:What do the three TV series have in common?
A．They are all about love.
B．They all describe what happened in ancient times.
C．They are all based on true stories.
D．They all feature time­travel.
小題3:If you are interested in prince and princess story, which will you turn into?
A．Rooftop Prince.B．Queen In­hyun's Man.
C．Dr Jin.D．Operation Proposal.

查看答案和解析>>

科目：高中英語 來源：不詳 題型：完形填空

There are times when people are so tired that they fall asleep almost anywhere. We can see there is a lot of sleeping on the bus or train on the       home from work in the evenings. A man will be       the newspaper, but seconds later，with his head down, it       as if he is trying to       it . Or he will fall asleep on the shoulder of the stranger       next to him.       place where unplanned short sleep       is in the lecture hall where a student will start snoring（打鼾）so       that the professor has to ask another student to       the sleeper awake. A more embarrassing（尷尬）situation happens when a student starts falling into sleep and the       of the head pushes the arm down off the       , and the movement causes the       of the body to move together and finally he falls down to the floor. The student wakes up on the floor with no       of the reason for getting there. The worst time to fall asleep is when       . Police reports are full of       that happen when people fall into sleep and go       the road. If the drivers are       , they are not seriously hurt. One woman’s car,       , went into the river. She woke up in four feet of       and thought it was raining. When people are really       , nothing will stop them from falling asleep—no matter where they are.
小題1:
A．trackB．wayC．pathD．road
小題2:
A．buyingB．foldingC．readingD．delivering
小題3:
A．a(chǎn)ctsB．showsC．looksD．sounds
小題4:
A．eat B．openC．findD．finish
小題5:
A．lyingB．waitingC．talkingD．sitting
小題6:
A．NextB．EveryC．AnotherD．One
小題7:
A．happensB．ends upC．lastsD．returns
小題8:
A．bravelyB．loudlyC．happilyD．carelessly
小題9:
A．leaveB．watchC．keepD．shake
小題10:
A．sizeB．shapeC．strengthD．weight
小題11:
A．bedB．deskC．shoulderD．book
小題12:
A．restB．positionC．a(chǎn)ctionD．side
小題13:
A．memoryB．problemC．questionD．purpose
小題14:
A．thinkingB．workingC．walkingD．driving
小題15:
A．changesB．eventsC．ideasD．a(chǎn)ccidents
小題16:
A．offB．upC．a(chǎn)longD．down
小題17:
A．luckyB．happyC．calmD．strong
小題18:
A．in timeB．a(chǎn)t firstC．a(chǎn)s usualD．for example
小題19:
A．dustB．grassC．waterD．bush
小題20:
A．lazyB．drunkC．lonelyD．tired

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

Water is the most common substance(物質(zhì)) found on the earth, but less than 1% of the earth’s water is suitable for drinking. More than 1,000,000,000 people around the world survive on just over 1 galon of water a day. Probebly more than 3,000,000,000 people may suffer from not having enough water by the year 2025. You are considered lucky if you live in a country where you can drink water out of your kitchen tap or bathroom tap. People in some countries have to pay for drinking water at home. So clean water is one of our most valuabe natural resources(資源).
In fact, peole waste so much clean water today. In factories lots of water is wasted. At home many people are not taking showers but still baths, and many are brushing their teeth with the tap turned on. Children are no longer taught how to save water….
You can save clean water in many ways. For example, if you keep gold fish, the tank water excellent for graden plants. And when you wash a milk bottle, pour the water on your house plants. Putting a brick or a water into your toilet tank many help use less water, saving many gallons over a long time.
Using rainwater is another simple way to save clean water. You can use rainwater to wash your hands after gardening, flush the toilet, and wash your car, your pet, your driveway when they are dirty.
For the same reason, people in Malaysia are encourageed to use rainwater. If one has a house with a small garden, he would buy a huge plastic tank to keep rainwater for their daily life.
小題1:We can learn from the passage ______.
A．when man can’t live without water
B．where there is no water resource
C．why there is less water on the earth
D．how important it is to save water
小題2:According to the passage, one of the ways to save water is _______.
A．to stop keeping gold fish
B．to pay much for drinking water
C．to use it in a clever way
D．to educate those who waste water
小題3:The underlined word “flush” in Paragraph 4 means “_______”.
A．clean something with water
B．pour water over something
C．make somehting wet with water
D．get water out of someghing
小題4:People are ecouraged to use rainwater _______.
A．so that is can make our life easier
B．so that clean water can be kept for other uses
C．because is it free and easy to get
D．because there is no claen water left for them

查看答案和解析>>

科目：高中英語 來源：不詳 題型：閱讀理解

You’ve just come home, after living abroad for a few years. Since you’ve been away, has this country changed for the better or for the worse?
If you’ve just arrived back in the UK after a fortnight’s holiday, small changes have probably surprised you—anything from a local greengrocer suddenly being replaced by a mobile-phone shop to someone in your street moving house.
So how have things changed to people coming back to Britain after seven, ten or even 15 years living abroad? What changes in society can they see that the rest of us have hardly noticed—or now take for granted? To find out, we asked some people who recently returned.
Debi: When we left, Cheltenham, my home town, was a town of white, middle-class families—all very conservative (保守的).The town is now home to many eastern Europeans and lots of Australians, who come here mainly to work in hotels and tourism. There are even several shops only for foreigners.
Having been an immigrant (移民) myself, I admire people who go overseas to find a job. Maybe if I lived in an inner city where unemployment was high, I’d think differently, but I believe foreign settlers have improved this country because they’re more open-minded and often work harder than the natives.
Christine: As we flew home over Britain, both of us remarked how green everything looked. But the differences between the place we’d left behind and the one we returned to were brought sharply into focus as soon as we landed.
To see policemen with guns in the airport for the first time was frightening — in Cyprus, they’re very relaxed — and I got pulled over by customs officers just for taking a woolen sweater with some metal-made buttons out of my case in the arrivals hall. Everyone seemed to be on guard. Even the airport car-hire firm wanted a credit card rather than cash because they said their vehicles had been used by bank robbers. But anyway, this is still a green, beautiful country. I just wish more people would appreciate what they’ve got.
小題1:After a short overseas holiday, people tend to ______ .         
A．expect small changesB．notice small changes
C．welcome small changesD．exaggerate (夸大) small changes
小題2:How does Debi look at the foreign settlers?
A．Cautiously.B．Skeptically.C．Positively.D．Critically.
小題3:When arriving at the airport in Britain, Christine was shocked by ______ .          
A．the tight securityB．the messy arrivals hall
C．the relaxed policemenD．the bank robbers
小題4:Which might be the best title for the passage?
A．Life in Britain.B．Britain in Memory.
C．Britain in Future.D．Back in Britain.

查看答案和解析>>

同步練習(xí)冊答案