Late-night DrinkingCoffee lovers beware. Having a quick "pick-me-up" cup of coffee late in

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 between 2 am and 4 am, 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 volunteers slept less well after a cup of caffeinated coffee than after drinking the same amount of decal. 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 - 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 decal after lunch.

The author mentions "pick-me-up" to indicate that

A．melatonin levels need to be raised.

B．neurohormone can wake us up.

C．coffee is a stimulant.

D．decaf is a caffeinated coffee.

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 between 2 am and 4 am, 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 Epiderniology 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 decal On average, subjects slept 336 minutes per night after drinking caffeinated coffee, compared with 415 minutes after decaf. They also took haft 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．melatonin levels need to be raised.

B．neurohormone can Wake us up.

C．coffee is a stimulant.

D．decal is a caffeinated coffee.

Late-night Drinking

Coffee lovers beware. Having a quick "pick-me-up" cup of coffee late in the day will play havoc with you sleep. As well as being a stimulant, caffeine interrupts the flow of melatonin, the brain hormone that send people into a sleep.

Melatonin levels normally start to rise about two hours before bedtime. Levels then peak between 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 Manrice Ohayon of the Stanford Sleep Epidemiklogy 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. 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-- and jigged around in 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 breakers were half those in decaf drinkers. 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 the drives melatonin production.

Because it can take many hours to eliminate caffeine from the body, Ohayon recommends that coffee lovers switch to decal after lunch.

The author mentions "pick-me-up" to indicate that______.

A．melatonin levels need to be raised

B．neurohormone can wake us up

C．coffee is stimulant

D．decaf is a caffeinated coffee

第二篇 Late-night Drinking

Coffee 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(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 riseabout two hours before bedtime. Levels then peak between 2 am and 4 am, before falling again. "It's theneurohormone (神经激素) thatcontrols our sleep and tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemi-ology Research Centerat Stanford University in California. But researchers inIsraelhavefound thatcaffeinated coffee halves the body's levels of this sleep hormone.

Lotan Shilo and a team at the SapirMedical Center in Tel Aviv University found that six volun-teers slept less well after a cup of caffeinated coffeethan after drinking the same amount of decaf (脱咖啡因咖啡). On average, subjects slept 336 minutes per night after drinkingcaffeinated coffee, com-pared with 415 minutes after decaf. They also took halfan hour to drop off, twice as long as usual

In the second phase of the experiment,the researchers woke the volunteers every three hours andasked them to give aurine (尿) sample. Shilo measured concentrations of abreakdown product of me-latonin. The results suggest that melatoninconcentrations in caffeine drinkers were half those in decafdrinkers. In apaper accepted for publication in Sleep Medicine, the researchers suggest thatcaffeineblocks production of the enzyme(酶)that drives melatonin production.

Because it can take many hours toeliminate caffeine from the body. Ohayon recommends that cof-fee lovers switchto decaf after lunch.

The author mentions"pick-me-up" to indicate that

A.melatonin levels need to be raised.

B.coffee is a stimulant.

C.neurohormone can wake us up.

D.caffeine can balance our brain hormone.

The new service is oriented towards ______.

A．non-mainstream music lovers

B．classic music lovers

C．symphonic music lovers

D．pop music lovers

Local people are protesting about the proposed ______ of a church into a late-night bar.

A．rumor

B．stability

C．argument

D．conversion

Local people are protesting about the proposed ______ of a church into a late-night bar.

A．rumor

B．stability

C．argument

D．conversion