共享题干题 (三) Late-Night Drinking根据下列的内容，回答下列的问题. 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, pared with 415 minutes after decaf. They also took half an hour to drop off—twice as long as usual--and jigged aroused 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 remends that coffee lovers switch to decal after lunch.1.[不定向选择题]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 2.[不定向选择题]What does Paragraph 3 mainly discuss?A.Different effects of caffeinated coffee and decal 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.
网友回答
1.参考答案：B
参考解析：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。
2.参考答案：A
参考解析：第三段涉及的是…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。3.[不定向选择题]What does the experiment mentioned in Paragraph 4 prove?A.There are more enzymes in decal 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.