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?
【小题1】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. |
| A．Through examples. |
| B．With comparisons. |
| C．Through cause and effect analysis. |
| D．By presenting research findings. |
| 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. |
| A．put up with | B．figure out | C．keep track of | D．take notice of |
【小题1】B
【小题2】B
【小题3】C
【小题4】B
解析试题分析：很多人有失眠的经历，那么大脑中有“睡眠开关”吗？科学家最近发现影响睡眠的除了生物钟，还有一种睡眠动态平衡系统，我们晚上睡觉的是两个技能的结合，科学家正在研究怎样通过睡眠动态平衡系统来改善我们的睡眠。
【小题1】主旨题：根据第四段的句子：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.可知这篇文章讲的是睡眠动态平衡系统的发现，选B。
【小题2】写作手法题：根据第四段的内容：可知作者解释睡眠动态平衡系统的的功能是通过和生物钟对比。选B
【小题3】细节题：从第五段的句子：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.可知让我们晚上睡觉的是两个技能的结合，选C
【小题4】猜词题：根据最后一段的句子：More importantly, figuring out how sleep mechanisms work may also help us to one day可知“unravel”的意思和前面的figure out相似，是“弄明白”，选B。
考点：考查科普类短文
阅读快车系列答案科目：高中英语 来源： 题型：阅读理解
Astronomy is the oldest science known to man. Thousands of years ago man looked at the stars and wondered about the heavens. But man was limited by what he could see with his eyes alone.
The Greeks studied astronomy over 2,000 years ago. They could see the size, color, and brightness of a star. They could see its place in the sky. They watched the stars move as the seasons changed. But the Greeks had no tools to help themselves study the heavens.
Each new tool added to the field of astronomy helped man reach out into space. They did not know that the planet called Saturn(土星) had rings around it. Their sight was so limited that they could not see all the planets. In the early 1700s, people thought there were only six planets. Nepture(海王星), the last of eight planets to be discovered, was not seen until 1846.
Before the spectroscope(分光镜), man did not know what kind of gases was in the sun or other stars. Without the radio telescope, we didn’t know that radio noises came from far out in space.
Today, astronomy is a growing science. We had learned more in the last fifty years than in the whole history of astronomy.
【小题1】. Thousands of years ago, people observed the stars with the limitation of their _____.
| A．eyesight | B．land |
| C．wealth | D．knowledge |
| A．know what the stars were made of |
| B．not see their places in the sky |
| C．help themselves study the heavens |
| D．watch the stars move as the seasons changed |
| A．telescopes | B．spectroscopes |
| C．radio telescopes | D．spaceships |
| A．Astronomy is the oldest science that humans have known. |
| B．Astronomy is developing fast with the help of technology. |
| C．In the early 1700s, people didn’t know the existence of Neptune. |
| D．Over 2,000 years ago, the Greeks knew the planet Saturn had rings around it. |
| A．tools used in astronomy |
| B．the development of astronomy in the last 50 years |
| C．Greeks’ achievements in astronomy |
| D．new tools and the development of astronomy |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Google has been collecting tons of data about smartphone usage around the world. Here are some of the most surprising and interesting facts：
Android is most popular in Japan, with 55% of respondents(调查对象) using it, compared with 39% for iOS.Android is also number one in a few other countries, including New Zealand (41%), the US(40%), and China (38%)．
iOS is farthest ahead in Switzerland, with 52% usage vs 23% for Android.Other countries where iOS is far ahead include Australia (49% vs 25% Android), Canada (45% vs 23% Android and 23% Blackberry), and France (43% vs 25% Android)．
In Egypt, Windows Mobile is far more popular than iOS.13% of survey respondents use the Microsoft smartphone platform, behind Symbian (19%) and Android (14%). iOS is very far down at 4%.
Mobile social networking is biggest in Mexico and Argentina, where 74% and 73% of users visit a social network daily.But mobilesocial is weak in Japan where 34% of users never visit a social network on their phone, and this figure rises to 41% in Brazil.
Watching video is most popular in Saudi Arabia, with 59% of respondents doing it daily.Number two is Egypt, with 41%.
Chinese users shop from their phones.59% of Chinese users do this, compared with only 41% in secondplace Egypt.Chinese users also love to write reviews.41% of them write a review of a local business after looking it up on their smartphone.Number two, Japan, is far behind, with only 24% of respondents doing this.
。
【小题1】Which of the following best describes the usage of the smartphone operating systems in Egypt?
| A．Windows Mobile＞iOS＞Symbian＞Android |
| B．Android＞Windows Mobile＞iOS＞Symbian |
| C．iOS＞Android＞Symbian＞Windows Mobile |
| D．Symbian＞Android＞Windows Mobile＞iOS |
| A．Brazil. | B．Japan. |
| C．Mexico. | D．Argentina. |
| A．Health. | B．Environment. |
| C．Technology. | D．Entertainment. |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Eating different colored foods can keep you healthy, as well as change your mood and behavior. Here is a list of colors, which can change your life.
Blue/Purple
Blue is considered to be peaceful and calming and it has the same effect on our health. The blue / purple color in food is due primarily to their anthocyanins which are antioxidants (抗氧化剂) that are particularly heart healthy and may help support healthy blood pressure. Out of all the blue and purple foods available, blueberries are considered to have the highest antioxidant level. An analysis of the latest data from the National Health and Nutrition Examination Study found that people who eat purple and blue fruits and vegetables are at a reduced risk for high blood pressure and are less likely to be overweight.
A food and health expert says that blue and purple color foods can prevent blood mass formation, and they also lower the risk of cancer.
Foods that contain blue and purple colors are: reddish eggplant (especially the skin), blueberries, blackberries, purple grapes, etc.
Green
We all know that we should eat green as green symbolizes nature. The green foods are rich in isothiocyanates, which help resist cancer.
Dr. Ashok Agarwal, a food and nutrition specialist, explains, "They are excellent sources of folic acid, vitamin K, as well as carotene （胡萝卜素）. Diets high in those above are associated with lowered blood pressure."
Foods that contain the green color are: broccoli, cabbage, cucumbers, etc.
Red
Lycopene (番茄红素) in reddish fruits and vegetables is a powerful antioxidant that has been associated with a reduced risk of some cancers, and also provides protection against heart attacks.
Dr. Smiths says, "Cooked tomato sauces are associated with greater health benefits as compared with the uncooked version as the heating process allows lycopene to be more easily absorbed by the body. Obtaining the most benefit from food depends on proper selection, storage and cooking of the produce."
Foods that contain red color are: Tomatoes and tomato products, watermelon, guava, red onions, red chili, red apples, red grapes, cherries, etc.
Orange
The orange foods are also rich in carotene, which are particularly good antioxidants. These foods are commonly considered eyesight foods because they contain vitamin A.
"Orange fruits and vegetables also play a part in preventing cancer, particularly of the lungs and stomach. Foods that contain the color orange are: Carrots, mangoes, sweet potatoes, pumpkins, etc.
【小题1】The passage tries to tell us that ______.
| A．colors mean a lot to people and their health |
| B．foods of different colors will have different benefits |
| C．eating foods with a color must prevent diseases |
| D．what people should eat in their daily lives |
| A．lowering blood pressure | B．improving eyesight |
| C．preventing cancer | D．reducing the risk of heart disease |
| A．Purple. | B．Green. | C．Red. | D．Orange. |
| A．vitamin A | B．folic acid | C．carotene | D．vitamin K |
| A．all grapes help lower the risk of high blood pressure and cancer |
| B．lung cancer can be prevented by eating red-colored foods |
| C．green-colored foods contain a lot of vitamin A which is good for eye health |
| D．tomatoes should be eaten cooked so that we can benefit the most |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Using too much water or throwing rubbish into our rivers are clear ways that humans can put our water supply in danger, but we also affect our water supply in less obvious ways. You may wonder how paving(铺砌) a road can lead to less useable fresh water. A major part of the water we use every day is groundwater. Groundwater does not come from lakes or rivers.It comes from underground. The more roads and parking lots we pave, the less water can flow into the ground to become groundwater.
Human activity is not responsible for all water shortages. Drier climates are of course more likely to have droughts than areas with more rainfall，but in any case, good management can help to make sure there is enough water to meet our basic needs.
Thinking about the way we use water every day can make a big difference, too. In the United States, a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live，but there's a lot we can do to lower the number.
You can take steps to save water in your home.To start with, use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher only when it is full. Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.
【小题1】Which of the following is most likely to lead to less groundwater?
| A．Using river water. | B．Throwing batteries away. |
| C．Paving parking lots. | D．Throwing rubbish into lakes. |
| A．All water shortages are due to human behavior. |
| B．It takes a lot of effort to meet our water needs. |
| C．There is much we can do to reduce family size. |
| D．The average family in America makes proper use of water. |
| A．show us how to fix leaks at home |
| B．tell us how to run a dishwasher |
| C．prove what drinking glass is best for us |
| D．suggest what we do to save water at home |
| A．why paving roads reduces our water |
| B．how much we depend on water to live |
| C．why droughts occur more in dry climates |
| D．how human activity affects our water supply |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Rising levels of carbon dioxide in the atmosphere are a major cause of climate change, and now a new study has confirmed that atmosphere CO2 is also affecting the ocean chemistry and potentially harming sea life.
Montana State University scientist Robert Dore has been researching the water in the Pacific Ocean for almost two decades. “We’ve been going to the same spot in the Pacific Ocean, and we try and characterize long-term change in the open ocean environment. And one of the key things that we measure is CO2 levels. And we’ve been able to record this increasing quantity of atmosphere CO2 into the ocean.”
Scientists expected that as atmosphere CO2 increased, more and more of the carbon dioxide would be absorbed into the ocean, affecting the chemical balance of the sea water, with a potentially harmful impact on shellfish and coral in particular.
“As carbon dioxide dissolves in the water or seawater in this case, it forms a weak acid, carbonic acid,” Dore explains. “And therefore, as the concentration of CO2 in the atmosphere goes up and that exchanges with the surface seawater, it drives the pH down, and makes it more acidic.”
The seawater samples Dore and his colleagues have analyzed confirm what the theory predicts.
The effect was particular striking at about 250 meters down, and again at 500 meters. Dore and his colleagues came up with two possible explanations. It could be that surface water picked up CO2 and then moved to those depths. Or there could be a biological explanation.
“It’s important to realize that the oceans are really becoming acidic. And it can have negative impacts on a whole variety of sea life from fish to coral. It’s potentially catastrophic.”
【小题1】What can be the best title of the passage?
| A．Scientist Researching Seawater |
| B．Sea Life Facing Danger |
| C．Oceans Becoming More Acidic |
| D．Climate Change Affecting Seawater |
| A．more corals will appear in the sea |
| B．the chemical balance of the seawater is affected |
| C．the surface water is becoming warmer |
| D．the pH of the ocean out here has been increasing |
| A．a→b→c→d→e | B．e→b→c→d→a |
| C．a→e→b→c→d | D．e→d→c→b→a |
| A．the expectation of other scientists |
| B．some former theory |
| C．his research and analysis |
| D．a major cause of climate change |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
A huge cloud of dust rose and an overpass disappeared. This was the scene in Zhuzhou，Hunan Province on May 17.Nine people were killed and 16 injured.
Things were similar last year in the Sichuan earthquake. Thousands of people were buried in the ruins and lost their lives. What if we could have warned them?
People are always racking their brains to find a way of preventing buildings’ collapse. Better materials and technology help，but they are not a solution.
Just like humans，a building has its own life cycle from “birth” to “death”．If we know when a building is going to collapse，we can repair it in advance or get out of it before it falls.
Now，scientists at the University of Illinois have developed a material that turns red before it breaks. The invention could be used in things like climbing ropes or bridge supports.
The research was led by Nancy Sottos，a professor at the university’s Beckman Institute，and Douglas Davis，a graduate research assistant.
The secret behind the colorchanging material is a type of molecule (分子)．A molecule is a group of atoms held together by chemical bonds. Imagine you and your friends standing in a circle，holding hands. Each person stands for one atom，your hands represent the bonds，and the entire circle represents a molecule. If one person lets go of his or her hands，the molecule changes color.
The research team put the molecule into a soft material. When the researchers stretched the material，it turned bright red for a few seconds before it broke into two pieces. When they repeatedly stretched and relaxed the material，without breaking it，it only turned a little red.
The major problem is that light can get rid of the red color. When the team shone bright light on the molecule，the broken bond was fixed，and the color disappeared.
If the bright light keeps the red color from appearing，the material’s warning system will be useless. Scientists still have a lot of work to do before the colorchanging molecules can be used outside the lab.
【小题1】What does the passage mainly introduce?
| A．The collapse of an overpass in Zhuzhou，Hunan Province. |
| B．The Sichuan earthquake |
| C．A material that turns red before it breaks. |
| D．A way of preventing building from collapsing. |
| A．suffering a lot | B．collecting beyond imagination |
| C．losing a lot | D．thinking very hard |
| A．Thousands of people died from the collapse of buildings in the Sichuan earthquake because they hadn’t been warned. |
| B．There is no building that will never collapse. |
| C．A new material has been applied to buildings to warn people of collapse. |
| D．A colorchanging material can turn red before it breaks. |
| A．The colorchanging molecules are certain to be used outside the lab. |
| B．There will be no collapse with the help of the colorchanging material. |
| C．There is a long way to go before the material can be applied. |
| D．The problem caused by bright light will be solved by scientists. |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
What will people die of 100 years from now? If you think that is a simple question, you have not been paying attention to the revolution that is taking place in biotechnology. With the help of new medicine, the human body will last a very long time. Death will come mainly from accidents, murder and war. Today's leading killers, such as heart disease, cancer, and aging itself, will become distant memories.
In discussion of technological changes, the Internet gets most of the attention these days. But the change in medicine can be the real technological event of our times. How long can humans live? Human brains were known to decide the final death. Cells are the basic units of all living things, and until recently, scientists were sure that the life of cells could not go much beyond 120 years because the basic materials of cells, such as those of brain cells, would not last forever. But the upper limits will be broken by new medicine. Sometime between 2050 and 2100, medicine will have advanced to the point at which every 10 years or so, people will be able to take medicine to repair their organs. The medicine, made up of the basic building materials of life, will build new brain cells, heart cells, and so on—in much the same way our bodies make new skin cells to take the place of old ones.
It is exciting to imagine that the advance in technology may be changing the most basic condition of human existence, but many technical problems still must be cleared up on the way to this wonderful future.
【小题1】According to the passage, human death is now mainly caused by ________.
| A．diseases and aging | B．accidents and war |
| C．accidents and aging | D．heart disease and war |
| A．medicine | B．the Internet | C．brain cells | D．human organ |
| A．heart disease will be far away from us |
| B．human brains can decide the final death |
| C．the basic materials of cells will last forever |
| D．human organs can be repaired by new medicine |
| A．Over 100 years. | B．More than 120 years. |
| C．About 150 years. | D．The passage doesn't tell us. |
| A．Cells aren’t the basic units of all living things any more |
| B．humans have to take medicine to build new skin cells now |
| C．much needs to be done before humans can have a longer life |
| D．we have already solved the technical problems in building new cells |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
When 18th-century scientists first came across Australia’s platypus(鸭嘴兽), they thought it was a trick. It is not surprising that the platypus made people confused. This funny-looking animal has feet and is a kind of warm-blooded mammal.
While other mammals usually keep their blood at around 37 degrees, the platypus has a lower body temperature of 32 degrees. As to its appearance, the platypus’mouth is not really like ducks’at all; its mouth actually looks a bit soft. The platypus closes its eyes when swimming. It uses its mouth to pick up outside information made by the creatures underwater.
Strangest of all, the platypus is a mammal that can lay eggs. And there is only one other kind of mammal that can lay eggs, the echidna (针鼹鼠) of Australia. Both the platy-pus and the echidna lay soft-shelled eggs, and both feed their young with their own milk that comes out of their skin. These animals also walk in a way that is similar to crocodiles(鳄鱼), with legs on the sides of their bodies rather than under them.
Though pretty, in a special way, the platypus is actually one of the few mammals that are poisonous. A male platypus has knife-like bones on its back legs which have enough poison to kill a dog.
The platypus has the honor of being one of the oldest mammals in the world. Until the early 20th century, it was hunted for its fur, but the situation has changed. Although the platypus is easily affected by pollution, it is not under any immediate threat.
【小题1】 What can we learn about the platypus according to the text?
| A．It has a lower body temperature than other mammals. |
| B．It only closes its eyes when underwater. |
| C．It’s the only poisonous mammal in the world. |
| D．It feeds its young on wild animal meat. |
| A．The crocodile. | B．The echidna. | C．The duck. | D．The dog. |
| A．its natural enemy | B．its appearance |
| C．its walking pose | D．its daily diet |
| A．is hunted for its meat | B．is in danger of extinction |
| C．is endangered by air pollution | D．is well-protected now |
| A．Platypus, a Trick? |
| B．Platypus, the Only Warm-Blooded Mammal |
| C．The Characteristics of Platypus |
| D．The Strange Mammal —Platypus。 |
查看答案和解析>>
湖北省互联网违法和不良信息举报平台 | 网上有害信息举报专区 | 电信诈骗举报专区 | 涉历史虚无主义有害信息举报专区 | 涉企侵权举报专区
违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com