单选题
单选题
Late-night Drinking
Coffee lovers beware. Having a quick “pick-me-up” cup of coffee1 late in the day will play havoc with2 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 between 2 am and 4 am, before falling again.3"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 Israelhave 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. 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 off4一 twice as long as usual 一 and jigged around5 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 suggest6 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.
词汇：
beware /bɪ"weə/ vi.当心；小心
stimulant/"stɪmjʊl(ə)nt/ n.兴奋剂
caffeine/"kæfiːn/ n.咖啡因
melatonin/,melə"təʊnɪn/ n.褪黑激素
hormone/"hɔːməʊn/ n.荷尔蒙,激素
neurohormone /,nʊro"hɔrmon; ,njʊro"hɔrmon/ n,神经激素
caffeinated /"kæfiəneitid/ adj.含咖啡因的;加入咖啡因的
halve /hɑːv/ vt. 二等分;减半
decaf/"diːkæf/ n.脱咖啡因咖啡
urine /"jʊərɪn; -raɪn/ n.尿
enzyme /"enzaɪm/ n. 酶
注释：
1. have a quick "pick-me-up" cup of coffee:喝一杯快速提神的咖啡。pick-me-up 意为“提神饮料”，这里用做定语。
2. play havoc with:干扰；对 造成严重破坏。例如：The noise of engines can play terrible havoc with a driver"s nerves.发动机的嘈杂声能严重扰乱驾驶员的神经。
3. Levels then peak between 2 am and 4 am, before falling again.褪黑激素的浓度在凌晨2 点和 4点之间达到最高值，然后再次下降。before在此处可以译为“然后”。
4. drop off:睡着。例如:He dropped off in the armchair.他在扶手椅上睡着了。
5. jig around:辗转反侧。jig:急动，蹦蹦跳跳。例如:Stop jigging about, Billy, and just stand still for a moment.别到处乱蹦，比利，稳稳地站一会儿。
6. suggest:在这里不作“建议”解，它的意思是“间接地表明；暗示”。例如:I’m not suggesting that the accident was your fault.我并不是说那事故是你的错。
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
Late-night Drinking
Coffee lovers beware. Having a quick “pick-me-up” cup of coffee1 late in the day will play havoc with2 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 between 2 am and 4 am, before falling again.3"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 Israelhave 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. 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 off4一 twice as long as usual 一 and jigged around5 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 suggest6 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.
词汇：
beware /bɪ"weə/ vi.当心；小心
stimulant/"stɪmjʊl(ə)nt/ n.兴奋剂
caffeine/"kæfiːn/ n.咖啡因
melatonin/,melə"təʊnɪn/ n.褪黑激素
hormone/"hɔːməʊn/ n.荷尔蒙,激素
neurohormone /,nʊro"hɔrmon; ,njʊro"hɔrmon/ n,神经激素
caffeinated /"kæfiəneitid/ adj.含咖啡因的;加入咖啡因的
halve /hɑːv/ vt. 二等分;减半
decaf/"diːkæf/ n.脱咖啡因咖啡
urine /"jʊərɪn; -raɪn/ n.尿
enzyme /"enzaɪm/ n. 酶
注释：
1. have a quick "pick-me-up" cup of coffee:喝一杯快速提神的咖啡。pick-me-up 意为“提神饮料”，这里用做定语。
2. play havoc with:干扰；对 造成严重破坏。例如：The noise of engines can play terrible havoc with a driver"s nerves.发动机的嘈杂声能严重扰乱驾驶员的神经。
3. Levels then peak between 2 am and 4 am, before falling again.褪黑激素的浓度在凌晨2 点和 4点之间达到最高值，然后再次下降。before在此处可以译为“然后”。
4. drop off:睡着。例如:He dropped off in the armchair.他在扶手椅上睡着了。
5. jig around:辗转反侧。jig:急动，蹦蹦跳跳。例如:Stop jigging about, Billy, and just stand still for a moment.别到处乱蹦，比利，稳稳地站一会儿。
6. suggest:在这里不作“建议”解，它的意思是“间接地表明；暗示”。例如:I’m not suggesting that the accident was your fault.我并不是说那事故是你的错。
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
Late-night Drinking
Coffee lovers beware. Having a quick “pick-me-up” cup of coffee1 late in the day will play havoc with2 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 between 2 am and 4 am, before falling again.3"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 Israelhave 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. 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 off4一 twice as long as usual 一 and jigged around5 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 suggest6 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.
词汇：
beware /bɪ"weə/ vi.当心；小心
stimulant/"stɪmjʊl(ə)nt/ n.兴奋剂
caffeine/"kæfiːn/ n.咖啡因
melatonin/,melə"təʊnɪn/ n.褪黑激素
hormone/"hɔːməʊn/ n.荷尔蒙,激素
neurohormone /,nʊro"hɔrmon; ,njʊro"hɔrmon/ n,神经激素
caffeinated /"kæfiəneitid/ adj.含咖啡因的;加入咖啡因的
halve /hɑːv/ vt. 二等分;减半
decaf/"diːkæf/ n.脱咖啡因咖啡
urine /"jʊərɪn; -raɪn/ n.尿
enzyme /"enzaɪm/ n. 酶
注释：
1. have a quick "pick-me-up" cup of coffee:喝一杯快速提神的咖啡。pick-me-up 意为“提神饮料”，这里用做定语。
2. play havoc with:干扰；对 造成严重破坏。例如：The noise of engines can play terrible havoc with a driver"s nerves.发动机的嘈杂声能严重扰乱驾驶员的神经。
3. Levels then peak between 2 am and 4 am, before falling again.褪黑激素的浓度在凌晨2 点和 4点之间达到最高值，然后再次下降。before在此处可以译为“然后”。
4. drop off:睡着。例如:He dropped off in the armchair.他在扶手椅上睡着了。
5. jig around:辗转反侧。jig:急动，蹦蹦跳跳。例如:Stop jigging about, Billy, and just stand still for a moment.别到处乱蹦，比利，稳稳地站一会儿。
6. suggest:在这里不作“建议”解，它的意思是“间接地表明；暗示”。例如:I’m not suggesting that the accident was your fault.我并不是说那事故是你的错。
The author of this passage probably agrees that____
A:coffee lovers sleep less than those who do not drink coffee B:we should not drink coffee after supper C:people sleep more soundly at midnight than at 3 am D:if we feel sleepy at night, we should go to bed immediately
Eat to Live
A meager diet may give you health and long life, but it"s not much fun—and it might not even be necessary. We may be able to hang on to 1 most of that youthful vigor even if we don"t start to diet until old age.
Stephen Spindler and his colleagues from the UniversityofCaliforniaatRiversidehave found that some of an elderly mouse"s liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation won"t reverse other damage caused by time for the mouse, but could help its liver metabolize drugs or get rid of toxins 2.
Spindler"s team fed three mice a normal diet for their whole lives, and fed another three on half-rations. Three more mice were switched from the normal diet to half-feed 3 for a month when they were 34 months old—equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers, and found that 46 changed with age in the normally fed mice. The changes were associated with things like inflammation and free radical production 4—probably bad news for mouse health. In the mice that had dieted all their lives, 27 of those 46 genes continued to behave like young genes. But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 per cent of these gene changes.
“This is the first indication that thee effects kick in 5 pretty quickly,” says Huber Warner from the National Institute on Aging near Washington, D. C.
No one yet knows if calorie works in people as it does in mice, bus Spindler is hopeful. “There"s attracting and tempting evidence out there that it will work,” he says.
If it does work in people, there might be good reasons for rejuvenating the liver. As we get older, out bodies are les efficient at metabolizing drugs, for example. A brief period of time of dieting, says Spindler, could be enough to make sure a drug is effective.
But Spindler isn"t sure the trade-off is worth it 6. “The mice get less disease, they live longer but they"re hungry,” he says. “Even seeing what a diet does, it"s still hard to go to a restaurant and say: "I can only eat half of that".”
Spindler hopes we soon won"t need to diet at all. His company, Life Span Genetics inCalifornia, is looking for drugs that have the effects of calorie restriction.
词汇：
meager ["mi:gə] adj.不足的
youthful [ˈju:θfl] adj.有青春活力的
vigor ["vɪgə] n.精力，活力
metabolize [mə"tæbəlaɪz] vt.使(一种物质)进入新陈代谢过程
genetic [dʒəˈnetɪk] adj.基因的
rejuvenation [rɪˌdʒu:və"neɪʃn] n.恢复活力，返老还童
注释：
1.hang on to:继续保留。例如：You should hang on to that painting -it might be worth a lot ofmoney one day.你应该继续保留那幅画，或许有一天它会值很多钱。
2. The genetic rejuvenation won"t reverse other damage caused by time for the mouse,but couldhelp its liver metabolize drugs or get rid of toxins.老鼠的肝部基因恢复活力不会逆转老鼠在其他方面的老化，但却有助于肝脏代谢药物或除去毒素。other damage caused by time岁月造成的其他方面的破坏，即“其他方面的老化”。metabolize drugs:代谢药物，即“使药物参与新陈代谢以提高药效”。get rid of:摆脱，除去。
3.half-rations和half-feed：都是指“老鼠饲料正常定量(normal diet)的一半”。
4.free radical production:指“（有机体组织、器官等的）无限激增”。
5.kick in:意为“开始起作用”。例如：We"re still waiting for the air conditioning to kick in．我们还在等着空调开始起作用。
6.be worth it：意为“值得，有益”。例如：They are expensive,but they are worth it．那些东西很贵，但划得来。
According to the last two paragraphs,Spindler believes that____.
A:calorie restriction is very important to young people B:seeing the effect of a diet,people will eat less than normal C:dieting is not a good method to give us health and a long life D:drugs do not have the effects of calorie restriction
乡罗提督战功，见于《圣武记》者详矣。其智能亦自可韬，非徒以武力雄一时也。公尝率兵入南山，搜余贼，村人苦猴群盗食田粮，晨必发火器惊之。公问故，令获一猴来，剃其毛，画面为大眼诸丑怪状。明晨俟群猴来，纵之去，皆惊走。后不复至。
官夔州游击，夔关临峡，山水迅急，瞬息千里，盐枭至则呜金叫呼，越关以过，船皆设炮械，两旁系大竹，弯如弓，他船追及，断系发之，船必覆，人莫敢撄。公募善泅者，持利锯匿上流水中，俟船过，附而锯其舵，抵关适断，船不能行，触石破，尽获之。
罗少亡赖，数行窃，令捕之杖毙，弃诸野。中夜而苏，匍匐至一老妪家，周之，乃改行，投身军营，骁勇冠绝侪辈。当赵金龙之乱，罗受命，与总督卢公坤往平之，贼已困，将擒矣。时宣宗以尚书宗室禧__督军，未至，诸公议待禧至，罗曰：“围久师怠，贼必遁。”遂违众一战，歼贼且尽。
罗每对人言生平作贼事，不少讳，并请文人历叙其事，洵奇男子也。改行后，始娶妻，忽患奇疾，百方不治，一道人过门曰：“有方可救，但得钱三十千乃能配药。”罗自念贫窭，安得三十千钱，语其妻曰：“吾病且死，汝亦饿死耳。苟鬻汝，得钱买药，则两活矣。”妻泣而从之，病果瘳。
罗既官游击乃遣人访其妻以重金赎还为夫妇如初报其鬻身救夫之义也此事不足训然以视少共艰苦既贵而厌弃其糟糠者其厚薄之区殆不可以道里计天生豪杰磊磊落落安得以道学家之律绳之。
A:其智能亦自可韬 B:语其妻曰…… C:非徒以武力雄一时也 D:越关以过，船皆设炮械 E:令捕之杖毙，弃诸野 F:妻泣而从之，病果瘳 G:遂违众一战，歼贼且尽 H:吾病且死，汝亦饿死耳
乡罗提督战功，见于《圣武记》者详矣。其智能亦自可韬，非徒以武力雄一时也。公尝率兵入南山，搜余贼，村人苦猴群盗食田粮，晨必发火器惊之。公问故，令获一猴来，剃其毛，画面为大眼诸丑怪状。明晨俟群猴来，纵之去，皆惊走。后不复至。
官夔州游击，夔关临峡，山水迅急，瞬息千里，盐枭至则呜金叫呼，越关以过，船皆设炮械，两旁系大竹，弯如弓，他船追及，断系发之，船必覆，人莫敢撄。公募善泅者，持利锯匿上流水中，俟船过，附而锯其舵，抵关适断，船不能行，触石破，尽获之。
罗少亡赖，数行窃，令捕之杖毙，弃诸野。中夜而苏，匍匐至一老妪家，周之，乃改行，投身军营，骁勇冠绝侪辈。当赵金龙之乱，罗受命，与总督卢公坤往平之，贼已困，将擒矣。时宣宗以尚书宗室禧__督军，未至，诸公议待禧至，罗曰：“围久师怠，贼必遁。”遂违众一战，歼贼且尽。
罗每对人言生平作贼事，不少讳，并请文人历叙其事，洵奇男子也。改行后，始娶妻，忽患奇疾，百方不治，一道人过门曰：“有方可救，但得钱三十千乃能配药。”罗自念贫窭，安得三十千钱，语其妻曰：“吾病且死，汝亦饿死耳。苟鬻汝，得钱买药，则两活矣。”妻泣而从之，病果瘳。
罗既官游击乃遣人访其妻以重金赎还为夫妇如初报其鬻身救夫之义也此事不足训然以视少共艰苦既贵而厌弃其糟糠者其厚薄之区殆不可以道里计天生豪杰磊磊落落安得以道学家之律绳之。
A:其智能亦自可韬 B:语其妻曰…… C:非徒以武力雄一时也 D:越关以过，船皆设炮械 E:令捕之杖毙，弃诸野 F:妻泣而从之，病果瘳 G:遂违众一战，歼贼且尽 H:吾病且死，汝亦饿死耳
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