EVERYONE has those nights – you lie in your bed for hours, tossing and turning, totally unable to fall asleep. You wish you could just turn your brain off as if it were a light. That would make things much easier, wouldn’t it?
Now it looks like you are one step closer to this wild dream of yours – scientists from Oxford University, UK have just discovered the “switch” that tells the brain to go to sleep, reported Forbes.
To understand the study, you first need to know that there are two mechanisms (机能) that regulate sleep. There’s one that we’re already familiar with – our body clock, which works in a 24-hour cycle based on the light changes throughout the day.
The other one is what scientists call the sleep “homeostat (动态平衡系统)”. This mechanism has nothing to do with daylight. Instead, it keeps track of the brain’s waking hours and urges it to rest if it has been awake for a long time. “It is similar to the thermostat (自动调温器) in your home. A thermostat measures temperature and switches on the heating if it’s too cold,” Professor Gero Miesenböck, who led the study, told The Telegraph.
Our bodies use both of the mechanisms to regulate sleep. “The body clock says it’s the right time, and the sleep thermostat has built up pressure during a long waking day,” explained Miesenböck.
There is no way that scientists can trick the body clock. But with the sleep homeostat, there might be something they can do.
The researchers found that the sleep homeostat works by activating a specific group of nerve cells, or neurons, in the brain. They tested their theory on fruit flies by removing the neurons from the insects’ brains. And as expected, they found that the flies without the homeostat neurons did not keep a regular sleep pattern anymore.
Now that scientists have pinpointed (定位) the exact place in the brain – or, the “switch” – that regulates sleep, they can begin investigating (研究) how to activate these cells at any given time so that people can be sent to sleep instantly.
More importantly, figuring out how sleep mechanisms work may also help us to one day unravel one of the oldest mysteries of all: why do we need to sleep in the first place?
What is the article mainly about?
| A．A new way to treat sleep disorders. |
| B．The discovery of the sleep “homeostat”. |
| C．Advice on what to do when you fail to fall asleep. |
| D．A comparison of the two mechanisms that regulate sleep. |
How does the author explain the function of the sleep homeostat?
| A．Through examples. |
| B．With comparisons. |
| C．Through cause and effect analysis. |
| D．By presenting research findings. |
What can we conclude from the article?
| A．Generally, the sleep homeostat has less effect on people during the day than at night. |
| B．There is little scientists can do to affect the way the sleep homeostat works. |
| C．What makes us go to sleep at night is probably a combination of the two mechanisms. |
| D．The more homeostat neurons there are in one’s brain, the more easily one can fall asleep. |
The underlined word “unravel” in the last paragraph is closest in meaning to ______.
| A．put up with | B．figure out | C．keep track of | D．take notice of |
Running like the wind, roaring (咆哮) like thunder, tigers have long been feared and respected as a king of the animal world. But last week a report said that there are no more than 30 wild tigers left in south China.
This was the conclusion of a team of scientists from China's State Forestry Administration and the World Nature Fund.
The South China tiger, also known as the Chinese tiger, is native to southern China. In the 1950's, there were over 4000 tigers found in mountain forests in the country. But due to the destruction of their natural habitat and uncontrolled hunting, it has been pushed on to the list of the world's top ten most endangered species.
Sixtysix of the big cats can be found in the cages of a dozen zoos around China. But they are nothing like their wild cousins. They have lost their natural skills such as hunting and killing. If they were set free they could not look after themselves.
“Breeding has damaged the quality of the species”， said Pei Enle, deputy director of the Shanghai Zoo.
To reintroduce the species into the wild, the country started a programme to send five to ten young tigers to South Africa. Four of them have already arrived. Progress has been made as two elder tigers have recovered some of their instincts(本能) and can hunt wild animals by themselves at the African base.
“South Africans are very experienced in reintroducing big animals to the wild. The country has very good natural conditions for the tigers to learn in”， said Lu Jun, office director of the National Wildlife Research and Development Center. “We tried in Fujian Province, but it was not successful as there was not a complete ecochain(生物链) and there was a lack of space.”
The tigers should return to China in 2007 when the reservations in Fujian are ready.What is the main reason for the South China tiger becoming one of the world's top ten most endangered species?
| A．Because it has lost its natural instincts. |
| B．Because there is not a complete ecochain. |
| C．Because there is no space for it. |
| D．Because uncontrolled hunting has destroyed its natural living conditions. |
How is the programme of sending several tigers to South Africa getting on?
| A．Its effect still remains to be seen. |
| B．Two tigers can already compete with their wild cousins. |
| C．Some of the tigers are already on the road to recovering their natural skills. |
| D．The tigers should be able to recover their instincts completely by 2007. |
By saying “but they are nothing like their wild cousins”， the writer means that________.
| A．they are no longer feared by other wild animals |
| B．they don't know how to hunt or kill |
| C．a complete change has resulted in the species because of breeding |
| D．to reintroduce them into the wild has become an urgent task |
What is the purpose of sending young tigers to South Africa?
| A．To help the tigers recover their ability to live in the wild. |
| B．To provide them with a better environment. |
| C．To get the tigers to go on a tour. |
| D．To find a complete ecochain for them. |
Which one is NOT the reason for South Africa being chosen as the training place?
| A．Because the tigers can hunt wild animals by themselves at the African base. |
| B．Because South Africans are skilled at dealing with the tigers. |
| C．Because there is a complete ecochain and enough space there. |
| D．Because the country has good natural conditions for the tigers to learn in. |
Since the 1970s, scientists have been searching for ways to link the brain with computers. Braincomputer interface (BCI) technology could help people with disabilities send commands to machines.
Recently, two researchers, Jose Millan and Michele Tavella from the Federal Polytechnic School in Lausanne, Switzerland, demonstrated (展示) a small robotic wheelchair directed by a person's thoughts.
In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.
“Our brain has billions of nerve cells. These send signals through the spinal cord (脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles.” Tavella says. “Our system allows disabled people to communicate with external world and also to control devices.”
The researchers designed a special cap for the user. This head cover picks up the signals from the scalp (头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.
Prof. Millan, the team leader, says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. “The practical possibilities that BCI technology offers to disabled people can be grouped in two categories: communication, and controlling devices. One example is this wheelchair.”
He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.BCI is a technology that can ________.
| A．help to update computer systems |
| B．link the human brain with computers |
| C．help the disabled to recover |
| D．control a person's thoughts |
How did Tavella operate the wheelchair in the laboratory?
| A．By controlling his muscles. |
| B．By talking to the machine. |
| C．By moving his hand. |
| D．By using his mind. |
Which of the following shows the path of the signals described in Paragraph 5?
| A．scalp→computer→cap→wheelchair |
| B．computer→cap→scalp→wheelchair |
| C．scalp→cap→computer→wheelchair |
| D．cap→computer→scalp→wheelchair |
The team will test with real patients to ________.
| A．make profits from them |
| B．prove the technology useful to them |
| C．make them live longer |
| D．learn about their physical condition |
Which of the following would be the best title for the text?
| A．Switzerland, the BCI Research Center |
| B．New Findings About How the Human Brain Works |
| C．BCI Could Mean More Freedom for the Disabled |
| D．Robotic Vehicles Could Help to Cure Brain Injuries |
Winter is a very special time in Northern Norway. Winter also means skiing, and Narvik can offer some of the best skiing in Norway. The view and light change frequently and no two days are the same. For many people, the northern lights are an unforgettable sight, and in Narvik the sky is especially clear and great for watching at night.
The tourist season lasts from February to April, although May can be fascinating too, often with fantastic dry snow and an unbelievable light lasting well into the evening.
Ski hire
It is possible for adults and children to hire skiing equipment such as snowboards. All equipment is prepared for us. If you would like to book your equipment, please email Narvikfjellet.
Cross-country skiing
There are 12 kilometers of cross country ski run in Narvik. You need to bring your own skis as there is no cross-country hire. However, equipment can be bought at local sports shops in and around Narvik.
Off-piste skiing（非场地滑雪）
In order to explore Narvik’s off-piste opportunities you need to know the dangers when choosing routes. It is suggested that you bring necessary equipment such as a shovel（雪铲）and a GPS locator. Ask Narvikfjellet for an experienced guide. With a guide you can explore Narvik’s special off-piste areas in a safe manner.
Sometimes it is nice to do something different and not everybody enjoys skiing. Then you can go horse-riding, or visit the local museums.
Price examples for the 2012--2013 season
| Time |
Children(8-15years) |
Adults |
| 1 day |
NOK 230 |
NOK 325 |
| 3 days |
NOK 590 |
NOK 835 |
| 5 days |
NOK 815 |
NOK 1,170 |
| 7 days |
NOK 970 |
NOK 1,375 |
| Children 0-7 years can enjoy the service for free |
In Northern Norway, the tourist season may last ______.
| A．one month | B．two months |
| C．three months | D．four months |
What can we know from the passage?
| A．You can book skiing equipment through the Internet. |
| B．You are provided with skiing equipment for free. |
| C．Narvik is located in the south of Norway. |
| D．Narvik is open to adults and children over eight. |
If Mr. and Mrs. Smith stay in Narvik with their six-year-old daughter for three days in 2012,they should pay ______.
| A．NOK 1,160 | B．NOK 1,425 |
| C．NOK 1,670 | D．NOK 2,260 |
Ask someone what they have done to help the environment recently and they will almost certainly mention recycling. Recycling in the home is very important of course. However, being forced to recycle often means we already have more material than we need.
We are dealing with the results of that over-consumption in the greenest way possible, but it would be far better if we did not need to bring so much material home in the first place. The total amount of packaging increased by 12% between 1999 and 2005. It now makes up a third of a typical household’s waste in the UK. In many supermarkets nowadays food items are packaged twice with plastic and cardboard. Too much packaging is doing serious damage to the environment. The UK, for example, is running out of it for carrying this unnecessary waste. If such packaging is burnt, it gives off greenhouse gases which go on to cause the greenhouse effect. Recycling helps, but the process itself uses energy. The solution is not to produce such items in the first place.
Food waste is a serious problem, too. Too many supermarkets encourage customers to buy more than they need. However, a few of them are coming round to the idea that this cannot continue, encouraging customers to reuse their plastic bags, for example. But this is not just about supermarkets. It is about all of us.
We have learned to associate packaging with quality. We have learned to think that something unpackaged is of poor quality. This is especially true of food. But is also applies to a wide range of consumer products, which often have far more packaging than necessary.
There are signs of hope. As more of us recycle, we are beginning to realize just how much unnecessary material are collecting. We need to face the wastefulness of our consumer culture, but we have a mountain to climb.The author uses figures in Paragraph 2 to show _______.
| A．the tendency of cutting household waste |
| B．the increase of packaging recycling |
| C．the rapid growth of super markets |
| D．the fact of packaging overuse |
According to the text, recycling ______.
| A．helps control the greenhouse effect |
| B．means burning packaging for energy |
| C．is the solution to gas shortage |
| D．leads to a waste of land |
What can be inferred from Paragraph 4?
| A．Unpackaged products are of bad quality. |
| B．Supermarkets care more about packaging. |
| C．It is improper to judge quality by packaging. |
| D．Other products are better packaged than food. |
What can we learn from the last paragraph?
| A．Fighting wastefulness is difficult. |
| B．Needless material is mostly recycled. |
| C．People like collecting recyclable waste. |
| D．The author is proud of their consumer culture. |
We know that sugary sodas aren’t good for our bodies. Now it turns out that they may not be good for our minds, either. A new study of more than 260,000 people has found a link between sweetened soft-drinks and depression, and diet sodas may be making matters worse.
Americans drink far more sodas than people in other countries— as much as 170 liters per person per year. But the impact of this study isn’t limited to the United States. “Sweetened drinks, coffee and tea are commonly consumed worldwide and have important physical consequences. And they may have important mental-health consequences as well,” study author Dr Honglei Chen said in a statement.
The study studied 263,925 people between the ages of 50 and 71. Researchers followed their consumption of drinks like soda, tea coffee, and other soft drinks from 1995 to 1996 and then. 10 years later, asked them if they had been diagnosed with depression since the year 2000. More than 11,3000 of them had.
Participants who drank more than four servings of sodas per day were 30 percent more likely to develop depression than participants who did not drink sodas at all. People who stuck with fruit punch(鸡尾酒), had a 38 percent higher risk than people who didn’t drink sweetened drinks. And all that extra sugar isn’t the actual problem. Researchers say that the artificial sweetener aspartame may be to blame.
The study found a link but could not surely determine whether sodas and other sweet soft drinks cause depression. Still, the results “are consistent with a small but growing body of evidence suggesting that artificially sweetened beverages may be linked to poor health outcomes.”
But there’s a bright side for those who can’t live without their daily sodas. Adults who drank coffee had a 10 percent lower risk of depression compared to people who didn’t drink any coffee, according to the study. “Our research suggests that cutting out or down on sweetened diet drinks or replacing them with unsweetened coffee may naturally help lower your depression risk,” said Chen.What has the new study of more than 260,000 people found?
| A．Sugary sodas aren’t good for the physical health of old people. |
| B．Americans have a special tooth for sweet foods. |
| C．Sweetened soft-drinks may increase the risk of depression. |
| D．Sweetened soft-drinks have important physical consequences. |
What do we know about the process of the study?
| A．About twenty-six thousand people participated in it. |
| B．The oldest participants were below 80 when the study was over. |
| C．Most of the participants had depression when the study was over. |
| D．The study lasted more than ten years from the beginning to the end. |
It is implied in the passage that ______.
| A．more research is needed to confirm the new findings |
| B．the new findings aren’t consistent with any previous findings |
| C．cutting one’s sodas intake will surely reduce one’s depression |
| D．the new findings won’t have an impact on people’s drinking habits |
What should you drink in order to reduce the risk of depression?
| A．Sodas. | B．Unsweetened coffee. |
| C．Sugary coffee. | D．Fruit punch. |