Can people change their skin color without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin color.
The gene comes in two versions, one of which is found in 99 percent of Europeans. The other is found in 93 to 100 percent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the color of a dark-striped zebra-fish（斑马鱼） to uniform gold by inserting a version of the pigment (色素) gene into a young fish. As with humans, zebra-fish skin color is determined by pigment cells, which contain melanin (黑色素). The number, size and darkness of melanin per pigment cell determine skin color.
It appears that, like the golden zebra-fish, light-skinned Europeans also have a mutation (变异) in the gene for melanin production. This results in less pigmented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebra-fish genes.
Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun (太阳光紫外线), which can cause skin cancer.
But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.
Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin color, said Cheng.
The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.
【小题1】The passage mainly tells us that ________.
| A．people can not change their skin color without any pain |
| B．the new discovery could lead to research into ways to change skin color safely |
| C．pop king Michael Jackson often changed his skin color as he liked |
| D．scientists have found out that people’s skin color is determined by the gene |
| A．nowadays people who want to change their skin color have to suffer a lot from the damage caused by the chemical treatment |
| B．Europeans and Africans have the same gene |
| C．the new discovery could help to find medical treatments for skin cancer |
| D．there are two kinds of genes |
| A．find the different genes of humans’ |
| B．prove the humans’ skin color is determined by the pigment gene |
| C．find out the reason why the Africans’ skin color is dark |
| D．find out the ways of changing people’s skin color |
| A．they are born light-skinned people |
| B．light-skinned Europeans have mutation in the gene for melanin production |
| C．they have fewer activities outside |
| D．they pay much attention to protecting their skin |
| A．neutral | B．negative | C．positive | D．unconcerned |
【小题1】D
【小题2】A
【小题3】B
【小题4】B
【小题5】C
解析试题分析：本文主要讲述基因决定人的肤色。将来人们想换肤色可能不需要象迈克杰克逊那样受罪了。
【小题1】主旨大意题 根据全文讲述的主要内容得知：科学家们发现人的肤色是由基因决定的。选D。
【小题2】A 推理判断题 从文章最后一句话It also could lead to research into ways to change skin color without damaging it like chemical treatment did on Michael Jackson.得知，人们改变肤色会象迈克尔·杰克逊那样受到化学药品对皮肤的伤害。选A。
【小题3】细节理解题 根据第三段的句子：As with humans, zebrafish skin color is determined by pigment cells, which contain melanin (黑色素).得知，因为斑马鱼和人类一样肤色中含有黑色素，所以科学家们以此来证明之。选B。
【小题4】推理判断题 根据第四段的句子：light-skinned Europeans also have a mutation (变异) in the gene for melanin production. This results in less pigmented skin.得知，因为欧洲人体内黑色素的基因发生了变异，所以他们的皮肤为浅肤色。选B。
【小题5】推理判断题 根据作者对基因决定人的肤色的论述以及文章首尾段可知，作者对此的态度是肯定的。选C。
考点：考查科普类短文
中考解读考点精练系列答案科目：高中英语 来源： 题型：阅读理解
Why do human beings still risk their lives under ground and doing one of the dirtiest and most dangerous jobs in the world？It’s an increasingly urgent question，given the recent highprofile(引人注目的) mining accidents in Sago，W.Va.and Huntington，Utah.A small group of engineers and robotics experts look forward to a day in the nottoodistant future when robots and other technology do most of the dangerous mining work.
Robotic technology，in particular，holds much promise，McAteer says，especially when it comes to mapping mines and rescuing trapped miners—the special operations of the mining industry.
One of the first mining robots was developed five years ago at CarnegieMellon University’s Robotics Institute.It was called Groundhog and it looked like a golf cart.It used lasers(激光器) to “see” in dark tunnels and map abandoned mines—some of the most dangerous work in the business.
The latest design is called Cave Crawler.It’s a bit smaller than Groundhog，and even more advanced.It can take photos and video and has sensors mounted(增加) that can detect the presence of dangerous gases.Incredibly，the robot has a real sense of logic.If it comes across an obstacle it gets confused.It has to think through the process and where to go next，and sometimes it throws_a_fit just like a real person.
The biggest obstacle，though，is cost.The original research project was federally funded，but that money has dried up，and it’s not clear where future funding will come from. Partly for that reason，and partly because of advances in safety，mining is not nearly as dangerous as it was in the past.Since 1990，fatalities(致命性) have declined by 67 percent and injuries by 51 percent，according to the National Mining Association.
Some experts predict that robots in mines will serve much of the same function that they do in the automotive industry.The robots do the most repetitive and dangerous jobs，but don’t eliminate(消除) the need for human workers.
【小题1】The underlined phrase “throws a fit” in Paragraph 4 probably means “________”．
| A．gets angry | B．gets sick |
| C．becomes hungry | D．becomes cheerful |
| A．robots in mines will serve much in the automotive industry |
| B．there will be no need for human workers in mines |
| C．the mine robots will have a very bright future |
| D．robots in mines have a long way to go |
| A．Mining robots do most of the mining work at present. |
| B．Groundhog can discover the presence of dangerous gases. |
| C．Experts are trying to make robots save miners in danger. |
| D．Robots cannot do dangerous work in dark areas. |
| A．Mining Accidents in America |
| B．Could Robots Replace Humans in Mines? |
| C．Cave Crawler，the Latest Robot |
| D．The Development of Robots |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Have you ever dreamed of visiting a planet in the Milk Way? While the trip sounds exciting, it would take years and years to reach your destination. So in the future, bedtime for astronauts may be more than a few hours of regular shut-eye. They would have to sleep for years.
European researchers are now conducting hibernation experiments. The study may help them understand whether humans could ever sleep through the years it would take for a space flight to distant planets. "If there was an effective technology, it could make deep-space travel a reality," said Mark Ayre of the European Space Agency last month.
What seems like science fiction is not completely unlikely. Researchers have been able to use chemicals to put living cells into a sleep-like state where they don't age. They have now moved on to small, non-hibernating mammals like rats. The results will be out by the end of 2004.
A major challenge is the fact that cells can be very simple systems, whereas body organs are far more complex.
"It's like moving from a simple Apple computer to a supercomputer," said Marco Biggiogera, a hibernation researcher at Italy's University of Pavia.
Just like bears and frogs, the hibernation of human beings would cause a person's metabolism (新陈代谢) to lower so they would need less energy.
Medical research, however, is just half of a space flight hibernation system.
There is the challenge of designing a suitable protective shelter. Such a shelter would provide the proper environment for hibernation, such as the proper temperature. It would also have to monitor (监控) life functions and serve the physiological needs of the hibernator.
According to Ayre, the six-person Human Outer Planets Exploration Mission to Jupiter's moon (木星的卫星) Callisto, could be an opportunity to use human hibernation. The mission aims to send six humans on a five-year flight to Callisto, where they will spend 30 days, in 2045.
【小题1】European researchers are conducting hibernation experiments to ________.
| A．ensure astronauts to get a complete sleep |
| B．find the secret of some creatures |
| C．make preparations for the journey to Jupiter’s moon Callisto |
| D．know if man can sleep for years |
| A．Science fiction is people’s imagination. |
| B．Science fiction is imaginative, but it can be realized. |
| C．Things seem impossible may come true. |
| D．Things described in science fiction are sure to become true. |
| A．putting living cells into a sleep-like state is full of failure |
| B．Biggiogera is confident with the experiment |
| C．human’s hibernation needs no energy |
| D．medical research is the key to space flight hibernation system |
| A．Six humans to fly to Callisto |
| B．Human hibernation improves health |
| C．Space travel attracts people |
| D．Deep sleep for deep space travel |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Most people know that awkward feeling when you walk into an elevator with other people and try not to make eye contact(接触). But a new research suggests it may be down to a subconscious power struggle being played out as you make your way up and down.
A study found that people decide where they stand based on a micro social status，established within seconds of entering the lift.
Rebekah Rousi．a Ph. D．student in cognitive(认知)science，conducted an ethnographic(人种论)
Study of elevator behaviour in two of the tallest office buildings in Adelaide，Australia.As part of her research，she took a total of 30 lift rides in the two buildings，and discovered .There was an established order to where people tended to stand
In a blog she writes that more senior men seemed to direct themselves towards the back of the elevator She said：“In front of them were younger men，and in front of them were women of aII ages.”She also notice there
was a difference in where people directed their gaze(注视)half way through the ride．“Men watched the monitors，looked in the side mirrors(in one building)to see themseIves．And in the door mirrors(of the other building)to also watch others Women would watch the monitors and avoid eye contact with other users(unless in conversation)and the mirrors，”she writes．
She concluded it could be that people who are shyer stand toward the front，where they can’t see other passengers，whereas confident people stand in the back，where they have a view of everyone else.
【小题1】The passage is mainly about
A. elevator riding manners
B communication in the elevator
C. elevator riders’ standing positions
D. micro social status in the elevator
【小题2】The underlined word“it”in the first paragraph probably refers to“ ”
| A．an elevator | B．the new research | C．eye contact | D．social status |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
October 15th is the Global Handwashing Day. Activities are planned in more than 20 countries to get millions of people in the developing world to wash their hands with soap. For example, donors（捐赠者） will give 150,000 bars of soap to schools in Ethiopia.
Experts say people around the world wash their hands every day, but very few use soap at so-called important moments. These include after using the toilet, after cleaning a baby and before touching food.
Global Handwashing Day is the idea of the Public-Private Partnership for Handwashing with Soap. Partners include the United Nations Children’s Fund, American government agencies, the World Bank and soap makers Unlever and Procter and Gamble. The organizers say all soaps are equally effective at removing disease-causing germ(细菌). They say the correct way to wash is to wet your hands with a small amount of water and cover them with soap. Rub（揉搓） it into all areas, including under the fingernails（指甲）. Rub for at least twenty seconds. Then rinse well under running water. Finally, dry your hands with a clean cloth or wave them in the air.
The Partnership for Handwashing says soap is important because it increases the time that people spend in washing hands. Soap also helps to break up the dirt that holds most of the germs. And it usually leaves a pleasant smell. The Partnership for Handwashing also says washing with soap before eating or after using the toilet could save more lives than any vaccine(疫苗)or medicine. Hand washing could also prevent the spread of other diseases. When people get germs on their hands, they can infect（感染）themselves by touching their eyes, noses or mouths. Then they can infect others.
【小题1】What’s the best title for this passage?
| A．Say no to washing hands in the wrong way. |
| B．Find out why washing hands carefully is so important. |
| C．Hand washing: so important----it gets a day of its own. |
| D．Want to live a longer life?-wash your hands. |
| A．to dry your hands | B．to wash away the soap |
| C．to rub your hands carefully | D．to clean your fingers |
| A．how to wash your hands correctly |
| B．why washing hand with soap is so important |
| C．the dangers of washing hands without soap |
| D．when we should especially wash our hands with soap |
| A．Medical care | B．Public service | C．Health report | D．Advertisement |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Recently we told you about a finding that more years of school could help students get higherscores on intelligence tests．That was the finding of a study of teenage males in Norway．Now，other research shows that physical activity may help students do better in their classes .
The research comes as educators in some countries are reducing time for activities like physical education．They are using the time instead for academic subjects like maths and reading．The studies appeared between 2007 and 2013．They included more than 55，000 children，aged 6 to 18．
Amika Singh：“Based on the results of our study，we can conclude that being physically active is beneficial for academic performance. There are，first，Physiological explanations，like more blood flow, and so more oxygen to the brain．Being physically active means there are more hormones(荷尔蒙)produced like endorphins(内啡肽)．And endorphins make your stress level lower and your mood improved, which means you also perform better.”
Also，students involved in organized sports learn rules and how to follow them．This could improve their classroom behavior and help them keep their mind on their work．
The study leaves some questions unanswered，however．Ms．Stash says it is not possible to say whether the amount or kind of activity affected the level of academic improvement．This is because of differences among the studies .
Also．they were mostly observational studies．An observational study is where researchers do not do controlled comparisons．They only describe what they observe．So they might observe a link that students who are more active often have better grades．But that does not necessarily mean being active was the cause of those higher grades．
The researchers said they found only two high - quality studies．They called for more high-
quality studies to confirm their findings．They also pointed out that “outcomes for other parts of the world may be quite different. ”
Still，the general finding was that physically active kids are more likely to do better in school．Ms．Singh says schools should consider that finding before they cut physical education programs．Her paper on “Physical Activity and Performance at School”is published in the Archives of Pediatric and Adolescent Medicine．
【小题1】The passage mainly tells us that ＿＿＿＿
| A．a research on physical education has been done by the researchers |
| B．there exists a possibility that physical activity leads to higher grades |
| C．the amount or kind of activity directly affects academic level |
| D．the research shows that the children aged 6 to 1 8 don't do sports |
| A．Being mentally active is good for academic subjects． |
| B．The more hormones you have，the more stressed you will get． |
| C．They have found many high-quality studies to prove the research． |
| D．The educators in the research think studies，not exercise，mean much to students． |
| A．good marks result from high-quality study |
| B．findings probably vary in different areas |
| C．physical activity will spread all over the world |
| D．academic performance depends on the surroundings |
| A．To call our attention to the sports at school． |
| B．To introduce all types of physical activities． |
| C．To represent the academic performance． |
| D．To improve students' health ． |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
The extraordinary Eastgate Building in Harare, Zimbabwe’s capital city, is said to be the only one in the world to use the same cooling and heating principles as the termite mound(白蚁堆).
Architect Mick Pearce used precisely the same strategy when designing the Eastgate Building, which has no air-conditioning and almost no heating. The building—the country’s largest commercial and shopping complex—uses less than 10% of the energy of a conventional building of its size. The Eastgate’s owners saved $3.5 million on a $36 million building because an air-conditioning equipment didn’t have to be imported.
The complex is actually two buildings linked by bridges across a shady, glass-roofed atrium(天井) open to the air. Fans suck fresh air in from the atrium, blow it upstairs through hollow spaces under the floors and from there into each office through baseboard vents(通风口). As it rises and warms, it is drawn out via ceiling vents and finally exists through forty-eight brick chimneys.
During summer’s cool nights, big fans blow air through the building seven times an hour to cool the empty floors. By day, smaller fans blow two changes of air an hour through the building, to circulate the air which has been in contact with the cool floors. For winter days, there are small heaters in the vents.
This is all possible only because Harare is 1600 feet above sea level, has cloudless skies, little dampness and rapid temperature changes—days as warm as 31℃ commonly drop to 14℃ at night. “You couldn’t do this in New York, with its hot summers and cold winters,” Pearce said.
The engineering firm of Ove Arup&Partners monitors daily temperatures. It is found that the temperature of the building has generally stayed between 23℃ and 25℃, with the exception of the annual hot period just before the summer rains in October and three days in November, when a doorkeeper accidentally switched off the fans at night. And the air is fresh—far more so than in air-conditioned buildings, where up to 30% of the air is recycled.
【小题1】Why was Eastgate cheaper to be built than a conventional building?
| A．It was designed in a smaller size. |
| B．No air conditioners were fixed in. |
| C．Its heating system was less advanced. |
| D．It used rather different building materials. |
| A．Fresh air from outside. | B．Heat in the building. |
| C．Hollow space. | D．Baseboard vent. |
| A．New York has less clear skies as Harare. |
| B．Its dampness affects the circulation of air. |
| C．New York covers a larger area than Harare. |
| D．Its temperature changes seasonally rather than daily. |
| A．allows a wide range of temperatures |
| B．functions well for most of the year |
| C．can recycle up to 30% of the air |
| D．works better in hot seasons |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
Scientists who discovered a new way of generating electricity from water say they may have come across an alternative source of clean energy to rival wind and solar power.
The breakthrough, which scientists say is the first new way to generate electricity in 160 years, could lead to batteries that use water instead of poisonous substances.
The scientists made the discovery when they were investigating what happens when tap water is forced through extremely narrow glass tubes. Water squeezed down the tubes, each of which was narrower than a tenth the thickness of a human hair, generating a small electric current that ran the length of the tube. To produce a larger electric current, the team tried forcing water through a glass water filter(滤水器)that contained thousands of narrow channels lined up side by side. “When we took a syringe(注射器)of water and squeezed it through the filter, we got enough power to light a light bulb,” said Larry Kostiuk of the University of Alberta in Canada. “The harder you push the syringe, the more electric current you get.”
The current is produced because of an effect in the glass tubes. When they are filled with water, positively charged ions(阳离子)fixed in the tubes are washed away, leaving a slight negative charge on the glass surface. When water is then forced along the tube, the surface repels negatively charged ions in the water while positively charged ions are attracted down the tube. The result is a net flow of positively charged ions that sets up an electric current.
According to Dr Kostiuk, no one has ever thought to use water to produce electricity in this way. “The last time someone came up with a way of generating electricity was Michael Faraday in 1839,” he said. “So this is the first new way of generating electricity in 160 years, which is why we are so excited about it.”
Dr Kostiuk says water batteries might one day be used to power mobile phones and calculators, but admitted that the engineering challenges might make other applications more realistic. “You’d need to be sure it wouldn’t leak, and you’d need to make sure it wouldn’t freeze,” he said.
More likely would be to install the electricity-generating devices where water is already being pumped, such as at city water filtration sites, he said. “It could compete with wind and solar power,” he added.
【小题1】What does the passage mainly want to tell us about?
| A．A kind of solar power discovered by scientists. |
| B．A kind of new energy source found in tap water. |
| C．The breakthrough to generate electricity 160 yeas ago. |
| D．A kind of new battery invented without poisonous substances. |
| A．rejects | B．identifies | C．attracts | D．rebels |
| A．They were the first to find a new way to produce electricity. |
| B．They could make an electric current to light a light bulb. |
| C．Their discovery could be used to invent water batteries. |
| D．Their discovery was made 160 years earlier than Faraday’s. |
| A．They must be used to power mobile phones and calculators. |
| B．They have some possible disadvantages like water leaking. |
| C．They would be needed greatly at city water filtration sites. |
| D．They would be better than wind and solar power. |
查看答案和解析>>
科目：高中英语 来源： 题型：阅读理解
You don't need to get in a time-traveling machine to see how technology will reshape our lives, such as the way we shop．Several new technologies that are to change your buying habits already exist．Let's see what's in store for your future shopping．
Try it on, virtually （虚拟的）．Want to shop online for a new pair of eyeglasses? You don't need to guess which pair looks best on you. Go and see the eBay Fashion iPhone app to try a pair of eyewear you're checking out on a picture of your face．But what if you want to buy something bigger? Thanks to Microsoft Kinect's motion tracking camera, you can cover clothes on your screen body．You can even choose the background of your virtual fitting room to enrich your shopping experience．
Get a perfect, custom fit．Everyone's body is shaped differently．To get a perfect fit, you sometimes have to get your clothes changed．But by using 3D scanning technology, all the clothes you buy will fit your body perfectly．Some companies scan your body using High-tech to get the most accurate measurements, so they can make special clothes just for you．
High-tech shopping carts and checkout counters．High-tech shopping carts could, in time, be a common sight in malls and supermarkets．Microsoft Kinect-enabled carts are currently under test．The cart can follow you along the aisles （通道）, controlled merely by your movement and your voice．In China, a supermarket chain introduced tablet-equipped carts that guide shoppers around the stores' aisles．
In the United States, several supermarkets use a device called Scan It that gives buyers the freedom to scan purchases on their own while they shop．While it's great not having to line up at a checkout counter, we wouldn't mind it if the store used Toshiba's new Object Recognition Scanner．The machine identifies a product as soon as it's placed in front of a camera just by its shape and color, even if it has no bar code．
【小题1】What's the best title for this text?
| A．Ways for future shopping |
| B．Influence of new technology |
| C．Inventions to change habits |
| D．A new time-traveling machine |
| A．make vivid pictures of our face |
| B．help us sell more clothes online |
| C．create us a virtual dressing room |
| D．choose suitable eyeglasses for us |
| A．Object Recognition Scanner． |
| B．The eBay Fashion iPhone app． |
| C．3D scanning technology． |
| D．Microsoft Kinect-enabled carts． |
| A．the customer's voice |
| B．its shape and color |
| C．the customer's movement |
| D．the bar code on it |
| A．Checkout counters will disappear from supermarkets in future． |
| B．Buyers can use Scan It to go around the supermarket by themselves． |
| C．High-tech shopping carts will be widely used in malls and supermarkets． |
| D．The new technologies are only dreams that are impossible to come true． |
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