共用题干Late-Night DrinkingCoffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. The author mentions" pick-me-up" to indicate that______.A: decaf is a caffeinated coffeeB: coffee is a stimulantC: neurohormone can wake us upD:melatonin levels need to be raised
共用题干
Late-Night Drinking
Coffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.
Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.
Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.
In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.
Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch.
Late-Night Drinking
Coffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.
Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.
Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.
In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.
Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch.
The author mentions" pick-me-up" to indicate that______.
A: decaf is a caffeinated coffee
B: coffee is a stimulant
C: neurohormone can wake us up
D:melatonin levels need to be raised
A: decaf is a caffeinated coffee
B: coffee is a stimulant
C: neurohormone can wake us up
D:melatonin levels need to be raised
参考解析
解析：pick-me-up指提神饮料，也就是一种刺激物，在这篇文章里具体指咖啡。所以，答案应选B。
由第二段第三句中“It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake”可知，控制我们睡眠的是神经激素。这一段的最后一个句子告诉我们“含咖啡因咖啡能使这种睡眠激素减半”。这正是咖啡因影响睡眠的原理。
第三段涉及的是一个实验，这个实验的目的是测试含咖啡因咖啡和脱咖啡因咖啡对睡眠的影响，该段主要谈论的是这个实验的现象。
第四段是第三段实验的继续，是该实验的第二个阶段。研究人员通过对志愿者尿样进行化验发现，咖啡因摄入者体内的褪黑激素仅为非咖啡因摄入者的一半。褪黑激素就是睡眠激素，所以，答案应该选D。
文章的结尾谈到，"Ohayon建议爱喝咖啡的人午饭后应该换喝脱咖啡因咖啡”。另外由第二段的内容可知，含咖啡因咖啡会使控制睡眠的激素减半，所以，作者大概会同意“晚饭后不应该喝咖啡”的说法。
由第二段第三句中“It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake”可知，控制我们睡眠的是神经激素。这一段的最后一个句子告诉我们“含咖啡因咖啡能使这种睡眠激素减半”。这正是咖啡因影响睡眠的原理。
第三段涉及的是一个实验，这个实验的目的是测试含咖啡因咖啡和脱咖啡因咖啡对睡眠的影响，该段主要谈论的是这个实验的现象。
第四段是第三段实验的继续，是该实验的第二个阶段。研究人员通过对志愿者尿样进行化验发现，咖啡因摄入者体内的褪黑激素仅为非咖啡因摄入者的一半。褪黑激素就是睡眠激素，所以，答案应该选D。
文章的结尾谈到，"Ohayon建议爱喝咖啡的人午饭后应该换喝脱咖啡因咖啡”。另外由第二段的内容可知，含咖啡因咖啡会使控制睡眠的激素减半，所以，作者大概会同意“晚饭后不应该喝咖啡”的说法。
相关考题：
共用题干Late-Night DrinkingCoffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. What does Paragraph 3 mainly discuss?A: Different effects of caffeinated coffee and decaf on sleep.B: Different findings of Lotan Shilo and a team about caffeine.C: The fact that the subjects slept 415 minutes per night after drinking decaf.D: The evidence that the subjects took half an hour to fall asleep.
共用题干第二篇Late-night DrinkingCoffee lovers,be careful.Having a quick "pick-me-up" cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,thebrain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak between 2 am and 4 am , before falling again. " It 's the neurohormone（神经激素）that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halvesthe body'S levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical center in Tel Aviv University found that six volunteers sleptless well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample.Shilo measured concentrations of a breakdown product of melatonin.The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body.Ohayon recommends that coffee lovers switch to decaf after lunch. The author mentions "pick-me-up" to indicate that_______.A:melatonin levels need to be raisedB:coffee is a stimulanC:neurohormone can wake us upD:caffeine can balance our brain hormone
共用题干Late-Night DrinkingCoffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. The author of this passage probably agrees that______.A: if we feel sleepy at night,we should go to bed immediatelyB: people sleep more soundly at midnight than at 3 a. mC: we should not drink coffee after supperD: coffee lovers sleep less than those who do not drink coffee
共用题干第二篇Late-night DrinkingCoffee lovers,be careful.Having a quick "pick-me-up" cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,thebrain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak between 2 am and 4 am , before falling again. " It 's the neurohormone（神经激素）that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halvesthe body'S levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical center in Tel Aviv University found that six volunteers sleptless well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample.Shilo measured concentrations of a breakdown product of melatonin.The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body.Ohayon recommends that coffee lovers switch to decaf after lunch.What does Paragraph 3 mainly discuss?A:Different effects of caffeinated coffee and decaf on sleep.B:Lotan Shilo'S research design on sleep.C:What the subjects did after drinking decaf at night.D:Why some subjects took half an hour to fall asleep.
共用题干第二篇Late-night DrinkingCoffee lovers,be careful.Having a quick "pick-me-up" cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,thebrain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak between 2 am and 4 am , before falling again. " It 's the neurohormone（神经激素）that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halvesthe body'S levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical center in Tel Aviv University found that six volunteers sleptless well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample.Shilo measured concentrations of a breakdown product of melatonin.The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body.Ohayon recommends that coffee lovers switch to decaf after lunch.The experiment mentioned in Paragraph 4 finds that caffeine drinkers________.A:produce less melatoninB:sleep longer than decaf drinkersC:produce more urine at nightD:wake up every three hours
共用题干第二篇Late-night DrinkingCoffee lovers,be careful.Having a quick "pick-me-up" cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,thebrain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak between 2 am and 4 am , before falling again. " It 's the neurohormone（神经激素）that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halvesthe body'S levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical center in Tel Aviv University found that six volunteers sleptless well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample.Shilo measured concentrations of a breakdown product of melatonin.The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body.Ohayon recommends that coffee lovers switch to decaf after lunch.Which of the following tells us how caffeine affects sleep?A:It blocks production of the enzyme that stops melatonin production.B:It interrupts the flow of the hormone that prevents people from sleeping.C:It halves the body's levels of sleep hormone.D:It stays in the body for many hours.
共用题干Late-Night DrinkingCoffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. Which of the following tells us how caffeine affects sleep?A: Caffeine blocks production of the enzyme that stops melatonin production.B: Caffeine interrupts the flow of the hormone that prevents people from sleeping.C: Caffeine halves the body's levels of sleep hormone.D: Caffeine stays in the body for many hours.
共用题干第二篇Late-night DrinkingCoffee lovers,be careful.Having a quick "pick-me-up" cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,thebrain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak between 2 am and 4 am , before falling again. " It 's the neurohormone（神经激素）that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halvesthe body'S levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical center in Tel Aviv University found that six volunteers sleptless well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample.Shilo measured concentrations of a breakdown product of melatonin.The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body.Ohayon recommends that coffee lovers switch to decaf after lunch.Ohayon advises coffee lovers_________.A: to drink less coffee during the dayB:to take decaf after lunchC:not to go to bed after taking coffeeD:not to drink coffee after supper
共用题干Late-Night DrinkingCoffee lovers beware .Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep.As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime.Levels then peak be-tween 2 a.m.and 4 a. m.,before falling again."It's the neurohormone that controls our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol- unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf（脱因咖啡）.On average , subjects slept 336 minutes per night after drinking caffeinated cof-fee,compared with 415 minutes after decaf. They also took half an hour to drop off-twice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample,Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers.In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. What does the experiment mentioned in Paragraph 4 prove?A: There are more enzymes in decaf drinkers' urine sample.B: There are more melatonin concentrations in caffeine drinkers' urine sample.C: Decaf drinkers produce less melatonin.D: Caffeine drinkers produce less sleep hormone.
共用题干第二篇CaffeineCaffeine is probably the most widely used drug in the world.Humans have been consuming caffeine for hundreds of years,primarily in the form of coffee,tea,and cocoa. Habitual coffee and tea drinkers had longbeen observed to have a lower incidence of non-melanoma（黑色素瘤）skin cancers , although no one knew why.A recent study found that caffeine affects skin cells damaged by ultraviolet radiation,a main cause of skin cancer. Caffeine interferes with a protein that cancerous cells need to survive,leaving the damaged cells to die before they become cancerous. Drinking caffeinated coffee has also been associated with a decreased incidence of endometrial（子宫内膜的）cancer-that is , cancer of the cells lining the uterus. The strongest effect appears to be in overweight women,who are at greatest risk for the disease.Researchers believe blood sugar,fat cells,and estrogen（雌性激素）may play a role. Although the mechanism remains unknown,peo- pie who drink more than two cups of coffee or tea a day reportedly have about half the risk of developing chronic liver disease as those who drink less than one cup of coffee daily;caffeinated coffee has also been as- sociated with lowered risk of cirrhosis（肝硬化）and liver cancer.While many of caffeine's undesirable effects,such as elevated heart rate and blood pressure,are brief, some short-term benefits,including pain relief,increased alertness,and increased physical endurance,have also been attributed to caffeine.As a component of numerous over-the-counter diet pills and pain relievers, caffeine increases their effectiveness and helps the body absorb them more quickly. By constricting（收缩） blood vessels in the brain , it can alleviate headaches一even migraines（偏头痛）一and can help counter the drowsiness（眩晕）caused by antihistamines（抗组胺药）.Caffeine does not alter the need for sleep,but it does offer a temporary solution to fatigue for people who need to stay alert. Research has shown that sleep-deprived individuals who consumed caffeine had improved memory and reasoning abilities,at least in the short term. Studies of runners and cyclists have shown that caffeine can improve their stamina一hence its addition to energy-boosting sports drinks.People who consume a lot of caffeine regularly may develop temporary withdrawal symptoms,headache being the most common,if they quit or cut back on it abruptly. Fortunately,these symptoms last only a day or two in most cases.Individuals who are more sensitive to the stimulatory side effects of caffeine may want to avoid it,but most doctors agree that the equivalent of three cups of coffee a day does not harm healthy people.There is no medical basis to give up daily caffeine and many reasons to include a moderate amount in one's diet.Cafffeine withdrawal symptoms_________.A:can become an ongoing problemB:may last as long as a weekC:are weight 1055 and mental disorderD:are usually short-lived
共用题干Late-night DrinkingCoffee lovers,be careful. Having a quick “pick-me-up” cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again.“It's the neurohormone（神经激素）that con-trols our sleep and tells our body when to sleep and when to wake,”says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average, subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample. Shilo measured concentrations of a break-down product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medi-cine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body. Ohayon recommends that coffee lovers switch to decaf after lunch.Which of the following tells us how caffeine affects sleep?A: It blocks production of the enzyme that stops melatonin production.B: It interrupts the flow of the hormone that prevents people from sleeping.C: It halves the body's levels of sleep hormone.D: It stays in the body for many hours.
共用题干Owls and Larks1 In this article,we look at the importance of sleep for learning. Most healthy adults need eight or more hours of sleep. But why do we need sleep in the first place?We need sleep for the brain to get a chance to rebuild memories stored during the day and associate these with previously learned things. If this process is interrupted by,say,the sound of an alarm clock,it may not be as effective. So if your sleep is cut short by the alarm clock,how dama- ging is it?The truth is that it's difficult to predict,as so much depends on how much sleep your body actually needs on that particular occasion.2 The popular belief that people are naturally either larks(early risers)or owls is false. The reason why people tend to be one or the other has more to do with lifestyle,age,and personality. Many people who appear to be early birds may have just become so through hab- it,for example,parents with very young children. Teenagers can have difficulty falling asleep until late at night and then they naturally have problems getting up the following morning.3 The main reason why owls are owls is that they tend to spend their time over a book, movie,or computer game till the early hours of the morning. They enjoy the quiet of the night when they can pursue their passion. On the other hand,larks can make better use of early morning hours where they can study in quiet at the time when their brains are most refreshed. So which is better for learning一an owl's or a lark's lifestyle?The simple truth is that it is more complex than simply being one or the other. Leading a well-balanced life in terms of work and play and sleeping enough to bring maximum refreshment is probably the secret.4 As for naps, experts on insomnia（失眠）argue against taking naps, as these may keep people up at night. If your nap lasts only five minutes to half an hour and does not affect your ability to fall asleep in the night,it will probably help you be more alert in evening hours.However,if you are having problems getting to sleep at night,it's not only naps that you should avoid. Try not to drink a lot of alcohol, take nicotine（尼古丁) , do mentally intense activities like preparing for exams or doing exercise in the evening. Some people swear that drinking coffee never stops them from sleeping like a log,whereas others will never go near the stuff for fear of being awake all night. However,the best advice for most is to avoid it in the evening,and if you drink coffee before a nap,remember you are likely to awaken as soon as the caffeine starts kicking in.A good lifestyle means one can______.A: sleep enough to bring most refreshmentB: keep away from coffee in the eveningC: stay up till the early hours of the morningD: get up quite earlyE: store memories in the brainF: rebuild memories stored during the day
共用题干Owls and Larks（猫头鹰与云雀）1 In this article,we look at the importance of sleep for learning. Most healthy adults need eight or more hours of sleep.But why do we need sleep in the first place?We need sleep for the brain to get a chance to rebuild memories stored during the day and associate these with previously learned things.If this process is interrupted by,say,the sound of an alarm clock,it may not be as effective.So if your sleep is cut short by the alarm clock,how damaging is it?The truth is that it's difficult to predict,as so much depends on how much sleep your body actually needs on that particular occasion.2 The popular belief that people are naturally either larks(early risers)or owls is false.The reason why people tend to be one or the other has more to do with lifestyle,age,and personality.Many people who appear to be early birds may have just become so through habit,for example,parents with very young chil-dren.Teenagers can have difficulty falling asleep until late at night and then they naturally have problems getting up the following morning.3 The main reason why owls are owls is that they tend to spend their time over a book,movie,or corn- puter game till the early hours of the morning.They enjoy the quiet of the night when they can pursue their passion.On the other hand,larks can make better use of early morning hours where they can study in quiet at the time when their brains are most refreshed.So which is better for learning一an owl's or a lark's lifestyle? The simple truth is that it is more complex than simply being one or the other. Leading a well-balanced life in terms of work and play and sleeping enough to bring maximum refreshment is probably the secret.4 As for naps , experts on insomnia（失眠）argue against taking naps , as these may keep people up at night. If your nap lasts only five minutes to haff an hour and does not affect your ability to fall asleep in the night,it will probably help you be more alert in evening hours.However,if you are having problems getting to sleep at night , it's not only naps that you should avoid. Try not to drink a lot of alcohol , take nicotine（尼古 丁）,do mentally intense activities like preparing for exams or doing exercise in the evening. Some peopleswear that drinking coffee never stops them from sleeping like a log,whereas others will never go near the stuff for fear of being awake all night.However,the best advice for most is to avoid it in the evening,and if you drink coffee before a nap,remember you are likely to awaken as soon as the caffeine starts kicking in.Sleep helps brain to________.A:stay up till the early hours of the morningB:sleep enough to bring most refreshmentC:rebuild memories stored during the dayD:store memories in the brainE:get up quite earlyF: keen away from coffee in the evening
共用题干Late-night DrinkingCoffee lovers,be careful. Having a quick “pick-me-up” cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again.“It's the neurohormone（神经激素）that con-trols our sleep and tells our body when to sleep and when to wake,”says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average, subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample. Shilo measured concentrations of a break-down product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medi-cine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body. Ohayon recommends that coffee lovers switch to decaf after lunch.The author mentions“pick-me-up” to indicate that______.A: melatonin levels need to be raisedB: coffee is a stimulantC: neurohormone can wake us upD: caffeine can balance our brain hormone
共用题干Late-night DrinkingCoffee lovers,be careful. Having a quick “pick-me-up” cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again.“It's the neurohormone（神经激素）that con-trols our sleep and tells our body when to sleep and when to wake,”says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average, subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample. Shilo measured concentrations of a break-down product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medi-cine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body. Ohayon recommends that coffee lovers switch to decaf after lunch.The experiment mentioned in paragraph 4 finds that caffeine drinkers______. A: produce less melatoninB: sleep longer than decaf drinkersC: produce more urine at nightD: wake up every three hours
共用题干Owls and Larks1 In this article,we look at the importance of sleep for learning. Most healthy adults need eight or more hours of sleep. But why do we need sleep in the first place?We need sleep for the brain to get a chance to rebuild memories stored during the day and associate these with previously learned things. If this process is interrupted by,say,the sound of an alarm clock,it may not be as effective. So if your sleep is cut short by the alarm clock,how dama- ging is it?The truth is that it's difficult to predict,as so much depends on how much sleep your body actually needs on that particular occasion.2 The popular belief that people are naturally either larks(early risers)or owls is false. The reason why people tend to be one or the other has more to do with lifestyle,age,and personality. Many people who appear to be early birds may have just become so through hab- it,for example,parents with very young children. Teenagers can have difficulty falling asleep until late at night and then they naturally have problems getting up the following morning.3 The main reason why owls are owls is that they tend to spend their time over a book, movie,or computer game till the early hours of the morning. They enjoy the quiet of the night when they can pursue their passion. On the other hand,larks can make better use of early morning hours where they can study in quiet at the time when their brains are most refreshed. So which is better for learning一an owl's or a lark's lifestyle?The simple truth is that it is more complex than simply being one or the other. Leading a well-balanced life in terms of work and play and sleeping enough to bring maximum refreshment is probably the secret.4 As for naps, experts on insomnia（失眠）argue against taking naps, as these may keep people up at night. If your nap lasts only five minutes to half an hour and does not affect your ability to fall asleep in the night,it will probably help you be more alert in evening hours.However,if you are having problems getting to sleep at night,it's not only naps that you should avoid. Try not to drink a lot of alcohol, take nicotine（尼古丁) , do mentally intense activities like preparing for exams or doing exercise in the evening. Some people swear that drinking coffee never stops them from sleeping like a log,whereas others will never go near the stuff for fear of being awake all night. However,the best advice for most is to avoid it in the evening,and if you drink coffee before a nap,remember you are likely to awaken as soon as the caffeine starts kicking in.Sleep helps brain to______.A: sleep enough to bring most refreshmentB: keep away from coffee in the eveningC: stay up till the early hours of the morningD: get up quite earlyE: store memories in the brainF: rebuild memories stored during the day
共用题干第二篇CaffeineCaffeine is probably the most widely used drug in the world.Humans have been consuming caffeine for hundreds of years,primarily in the form of coffee,tea,and cocoa. Habitual coffee and tea drinkers had longbeen observed to have a lower incidence of non-melanoma（黑色素瘤）skin cancers , although no one knew why.A recent study found that caffeine affects skin cells damaged by ultraviolet radiation,a main cause of skin cancer. Caffeine interferes with a protein that cancerous cells need to survive,leaving the damaged cells to die before they become cancerous. Drinking caffeinated coffee has also been associated with a decreased incidence of endometrial（子宫内膜的）cancer-that is , cancer of the cells lining the uterus. The strongest effect appears to be in overweight women,who are at greatest risk for the disease.Researchers believe blood sugar,fat cells,and estrogen（雌性激素）may play a role. Although the mechanism remains unknown,peo- pie who drink more than two cups of coffee or tea a day reportedly have about half the risk of developing chronic liver disease as those who drink less than one cup of coffee daily;caffeinated coffee has also been as- sociated with lowered risk of cirrhosis（肝硬化）and liver cancer.While many of caffeine's undesirable effects,such as elevated heart rate and blood pressure,are brief, some short-term benefits,including pain relief,increased alertness,and increased physical endurance,have also been attributed to caffeine.As a component of numerous over-the-counter diet pills and pain relievers, caffeine increases their effectiveness and helps the body absorb them more quickly. By constricting（收缩） blood vessels in the brain , it can alleviate headaches一even migraines（偏头痛）一and can help counter the drowsiness（眩晕）caused by antihistamines（抗组胺药）.Caffeine does not alter the need for sleep,but it does offer a temporary solution to fatigue for people who need to stay alert. Research has shown that sleep-deprived individuals who consumed caffeine had improved memory and reasoning abilities,at least in the short term. Studies of runners and cyclists have shown that caffeine can improve their stamina一hence its addition to energy-boosting sports drinks.People who consume a lot of caffeine regularly may develop temporary withdrawal symptoms,headache being the most common,if they quit or cut back on it abruptly. Fortunately,these symptoms last only a day or two in most cases.Individuals who are more sensitive to the stimulatory side effects of caffeine may want to avoid it,but most doctors agree that the equivalent of three cups of coffee a day does not harm healthy people.There is no medical basis to give up daily caffeine and many reasons to include a moderate amount in one's diet.Some athletes use caffeine to_________.A:improve their speedB:increase their enduranceC:maintain their alertnessD:relax their muscles
共用题干Late-night DrinkingCoffee lovers,be careful. Having a quick “pick-me-up” cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again.“It's the neurohormone（神经激素）that con-trols our sleep and tells our body when to sleep and when to wake,”says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average, subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample. Shilo measured concentrations of a break-down product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medi-cine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body. Ohayon recommends that coffee lovers switch to decaf after lunch.Ohayon advises coffee lovers______.A: to drink less coffee during the dayB: to take decaf after lunchC: not to go to bed after taking coffeeD: not to drink coffee after supper
共用题干Late-night DrinkingCoffee lovers,be careful. Having a quick “pick-me-up” cup of coffee late in the day will interrupt your sleep. As well as being a stimulant（兴奋剂）,caffeine interrupts the flow of melatonin（褪黑激素）,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again.“It's the neurohormone（神经激素）that con-trols our sleep and tells our body when to sleep and when to wake,”says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California. But researchers in Israel have found that caffeinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decaf（脱咖啡因咖啡）.On average, subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop off,twice as long as usual.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine（尿）sample. Shilo measured concentrations of a break-down product of melatonin. The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers. In a paper accepted for publication in Sleep Medi-cine,the researchers suggest that caffeine blocks production of the enzyme（酶）that drives melatonin production.Because it can take many hours to eliminate caffeine from the body. Ohayon recommends that coffee lovers switch to decaf after lunch.What does paragraph 3 mainly discuss?A: Different effects of caffeinated coffee and decaf on sleep.B: Lotan Shilo's research design on sleep.C: What the subjects did after drinking decaf at night.D: Why some subjects took half an hour to all asleep.
共用题干第二篇CaffeineCaffeine is probably the most widely used drug in the world.Humans have been consuming caffeine for hundreds of years,primarily in the form of coffee,tea,and cocoa. Habitual coffee and tea drinkers had longbeen observed to have a lower incidence of non-melanoma（黑色素瘤）skin cancers , although no one knew why.A recent study found that caffeine affects skin cells damaged by ultraviolet radiation,a main cause of skin cancer. Caffeine interferes with a protein that cancerous cells need to survive,leaving the damaged cells to die before they become cancerous. Drinking caffeinated coffee has also been associated with a decreased incidence of endometrial（子宫内膜的）cancer-that is , cancer of the cells lining the uterus. The strongest effect appears to be in overweight women,who are at greatest risk for the disease.Researchers believe blood sugar,fat cells,and estrogen（雌性激素）may play a role. Although the mechanism remains unknown,peo- pie who drink more than two cups of coffee or tea a day reportedly have about half the risk of developing chronic liver disease as those who drink less than one cup of coffee daily;caffeinated coffee has also been as- sociated with lowered risk of cirrhosis（肝硬化）and liver cancer.While many of caffeine's undesirable effects,such as elevated heart rate and blood pressure,are brief, some short-term benefits,including pain relief,increased alertness,and increased physical endurance,have also been attributed to caffeine.As a component of numerous over-the-counter diet pills and pain relievers, caffeine increases their effectiveness and helps the body absorb them more quickly. By constricting（收缩） blood vessels in the brain , it can alleviate headaches一even migraines（偏头痛）一and can help counter the drowsiness（眩晕）caused by antihistamines（抗组胺药）.Caffeine does not alter the need for sleep,but it does offer a temporary solution to fatigue for people who need to stay alert. Research has shown that sleep-deprived individuals who consumed caffeine had improved memory and reasoning abilities,at least in the short term. Studies of runners and cyclists have shown that caffeine can improve their stamina一hence its addition to energy-boosting sports drinks.People who consume a lot of caffeine regularly may develop temporary withdrawal symptoms,headache being the most common,if they quit or cut back on it abruptly. Fortunately,these symptoms last only a day or two in most cases.Individuals who are more sensitive to the stimulatory side effects of caffeine may want to avoid it,but most doctors agree that the equivalent of three cups of coffee a day does not harm healthy people.There is no medical basis to give up daily caffeine and many reasons to include a moderate amount in one's diet.Drinking coffee or tea may help_________.A:lower the incidence of being overweightB:lower the incidence of non-melanoma skin cancerC:increase the incidence of endometrial cancer D: increase the incidence of liver cancer
共用题干Owls and Larks1 In this article,we look at the importance of sleep for learning. Most healthy adults need eight or more hours of sleep. But why do we need sleep in the first place?We need sleep for the brain to get a chance to rebuild memories stored during the day and associate these with previously learned things. If this process is interrupted by,say,the sound of an alarm clock,it may not be as effective. So if your sleep is cut short by the alarm clock,how dama- ging is it?The truth is that it's difficult to predict,as so much depends on how much sleep your body actually needs on that particular occasion.2 The popular belief that people are naturally either larks(early risers)or owls is false. The reason why people tend to be one or the other has more to do with lifestyle,age,and personality. Many people who appear to be early birds may have just become so through hab- it,for example,parents with very young children. Teenagers can have difficulty falling asleep until late at night and then they naturally have problems getting up the following morning.3 The main reason why owls are owls is that they tend to spend their time over a book, movie,or computer game till the early hours of the morning. They enjoy the quiet of the night when they can pursue their passion. On the other hand,larks can make better use of early morning hours where they can study in quiet at the time when their brains are most refreshed. So which is better for learning一an owl's or a lark's lifestyle?The simple truth is that it is more complex than simply being one or the other. Leading a well-balanced life in terms of work and play and sleeping enough to bring maximum refreshment is probably the secret.4 As for naps, experts on insomnia（失眠）argue against taking naps, as these may keep people up at night. If your nap lasts only five minutes to half an hour and does not affect your ability to fall asleep in the night,it will probably help you be more alert in evening hours.However,if you are having problems getting to sleep at night,it's not only naps that you should avoid. Try not to drink a lot of alcohol, take nicotine（尼古丁) , do mentally intense activities like preparing for exams or doing exercise in the evening. Some people swear that drinking coffee never stops them from sleeping like a log,whereas others will never go near the stuff for fear of being awake all night. However,the best advice for most is to avoid it in the evening,and if you drink coffee before a nap,remember you are likely to awaken as soon as the caffeine starts kicking in.It is good advice for most people to______.A: sleep enough to bring most refreshmentB: keep away from coffee in the eveningC: stay up till the early hours of the morningD: get up quite earlyE: store memories in the brainF: rebuild memories stored during the day
共用题干第二篇CaffeineCaffeine is probably the most widely used drug in the world.Humans have been consuming caffeine for hundreds of years,primarily in the form of coffee,tea,and cocoa. Habitual coffee and tea drinkers had longbeen observed to have a lower incidence of non-melanoma（黑色素瘤）skin cancers , although no one knew why.A recent study found that caffeine affects skin cells damaged by ultraviolet radiation,a main cause of skin cancer. Caffeine interferes with a protein that cancerous cells need to survive,leaving the damaged cells to die before they become cancerous. Drinking caffeinated coffee has also been associated with a decreased incidence of endometrial（子宫内膜的）cancer-that is , cancer of the cells lining the uterus. The strongest effect appears to be in overweight women,who are at greatest risk for the disease.Researchers believe blood sugar,fat cells,and estrogen（雌性激素）may play a role. Although the mechanism remains unknown,peo- pie who drink more than two cups of coffee or tea a day reportedly have about half the risk of developing chronic liver disease as those who drink less than one cup of coffee daily;caffeinated coffee has also been as- sociated with lowered risk of cirrhosis（肝硬化）and liver cancer.While many of caffeine's undesirable effects,such as elevated heart rate and blood pressure,are brief, some short-term benefits,including pain relief,increased alertness,and increased physical endurance,have also been attributed to caffeine.As a component of numerous over-the-counter diet pills and pain relievers, caffeine increases their effectiveness and helps the body absorb them more quickly. By constricting（收缩） blood vessels in the brain , it can alleviate headaches一even migraines（偏头痛）一and can help counter the drowsiness（眩晕）caused by antihistamines（抗组胺药）.Caffeine does not alter the need for sleep,but it does offer a temporary solution to fatigue for people who need to stay alert. Research has shown that sleep-deprived individuals who consumed caffeine had improved memory and reasoning abilities,at least in the short term. Studies of runners and cyclists have shown that caffeine can improve their stamina一hence its addition to energy-boosting sports drinks.People who consume a lot of caffeine regularly may develop temporary withdrawal symptoms,headache being the most common,if they quit or cut back on it abruptly. Fortunately,these symptoms last only a day or two in most cases.Individuals who are more sensitive to the stimulatory side effects of caffeine may want to avoid it,but most doctors agree that the equivalent of three cups of coffee a day does not harm healthy people.There is no medical basis to give up daily caffeine and many reasons to include a moderate amount in one's diet.Drinking three cups of coffee a day_________.A:may not be recommended by most doctorsB:15 harmful to healthy peopleC:will probably not cause problemsD:may benefit sensitive people
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. What does the experiment mentioned in paragraph 4 prove?A: There are more enzymes in decaf drinkers' urine sample.B: There are more melatonin concentrations in caffeine drinkers' urine sample.C: Decaf drinkers produce less melatonin.D: Caffeine drinkers produce less sleep hormone that decaf drinkers.
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. The author of this passage probably agrees that______.A: coffee lovers sleep less than those who do not drink coffeeB: we should not drink coffee after supperC: people sleep more soundly at midnight than at 3 a.m.D: if we feel sleepy at night,we should go to bed immediately
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. Which of the following tells us how caffeine affects sleep?A: Caffeine blocks production of the enzyme that stops melatonin production.B: Caffeine interrupts the flow of the hormone that prevents people from sleeping.C: Caffeine halves the body's levels of sleep hormone.D: Caffeine stays in the body for many hours.
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. The author mentions"pick-me-up" to indicate that______.A: melatonin levels need to be raisedB: neurohormone can wake us upC: coffee is a stimulantD: decaf is a caffeinated coffee
共用题干Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. What does paragraph 3 mainly talk about?A: Different effects of caffeinated coffee and decaf on sleep.B: Different findings of Lotan Shilo and a team about caffeine.C: The fact that the subjects slept 415 minutes per night after drinking decaf.D: The proof that the subjects took half an hour to fall asleep.