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(huì)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(cuò)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(cuò)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(cuò)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(huì)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(huì)傳遞給我們的大腦錯(cuò)誤的信息，讓大腦以為還在白天，因此會(huì)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。
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科目：高中英語 來源：不詳 題型：閱讀理解

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A．a(chǎn)ctsB．showsC．looksD．sounds
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A．lyingB．waitingC．talkingD．sitting
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A．in timeB．a(chǎn)t firstC．a(chǎn)s usualD．for example
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A．dustB．grassC．waterD．bush
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B．where there is no water resource
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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
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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?
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A．the tight securityB．the messy arrivals hall
C．the relaxed policemenD．the bank robbers
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A．Life in Britain.B．Britain in Memory.
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