Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour. The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the colour of a dark-striped zebra fish to uniform gold by inserting a version of the pigment (色素) gene into a young fish. As with humans, zebra fish skin colour is determined by pigment cells, which contain melanosomes (黑色素体). The number, size and darkness of melanosomes per pigment cell determines skin colour.
It appears that, like the golden zebra fish, light-skinned Europeans also have a mutation (突变)in the gene for melanosome 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, 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 colours, said Cheng.
The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment done on Michael Jackson.
【小题1】According to the passage, scientists have found .
| A．people living in northern latitudes need more sunlight |
| B．the reason why people change their skin colour |
| C．the reason why people get skin cancer |
| D．the gene that determines skin colour |
| A．people like to change their skin colour |
| B．a mutation in the gene for melanosome production is different in human and zebra fish gene |
| C．people will be able to change their skin colour without chemical treatment in the future |
| D．skin cancer can be cured now |
| A．The version of the pigment gene of Asians and that of Africans are the same. |
| B．Scientists have succeeded in turning the colour of a dark-striped zebra fish into uniform gold. |
| C．Dark skin can protect bodies from utral-violet rays of the sun. |
| D．People like pop king Michael Jackson. |
| A．a novel | B．a science report |
| C．a story book | D．a science fiction |
【小题1】D
【小题2】C
【小题3】D
【小题4】B
解析试题分析：文章大意：本文主要讲述基因决定人的肤色。但是科学家已经发现可以用化学药品改变肤色。
【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】推理判断题 从文章第二段的句子Scientists have changed the colour of a dark-striped zebra fish to uniform gold by inserting a version of the pigment (色素) gene into a young fish.：得知，人们可以用化学药品改变肤色。选C。
【小题3】细节理解题：从第四段的句子：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 colours, said Cheng. 可知A是对的，从第二段的句子：Scientists have changed the colour of a dark-striped zebra fish to uniform gold by inserting a version of the pigment (色素) gene into a young fish.可知B是对的，从第四段的句子：Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun, which can cause skin cancer.可知C是对的，但是文章没有提到人们喜欢杰克逊。选D。
【小题4】推理判断题，本文主要讲述基因决定人的肤色。但是科学家已经发现可以用化学药品改变肤色。所以是一篇科普文章，应该选自科学报告。选B。
考点：考查科普类短文
新课标阶梯阅读训练系列答案科目：高中英语 来源： 题型：阅读理解
Winter begins in the north on December 22nd. People and animals have been doing what they always do to prepare for the colder months. Squirrels (松鼠), for example, have been busy gathering nuts from trees. Well, scientists have been busy gathering information about what the squirrels do with the food they collect.
They examined differences between red squirrels and gray squirrels in the American state of Indiana. The scientists wanted to know how these differences could affect the growth of black walnut (黑胡桃) trees. The black walnut is the nut of choice for both kinds of squirrels. The black walnut tree is also a central part of some hardwood forests.
Rob Swihart of Purdue University did the study with Jake Goheen, a former Purdue student now at the University of New Mexico. The two researchers estimate that several times as many walnuts grow when gathered by gray squirrels as compared to red squirrels. Gray squirrels and red squirrels do not store nuts and seeds in the same way. Gray squirrels bury nuts one at a time in a number of places. But they seldom remember where they buried every nut. So some nuts remain in the ground. Conditions are right for them to develop and grow the following spring. Red squirrels, however, store large groups of nuts above ground. Professor Swihart calls “death traps for seeds”.
Gray squirrels are native to Indiana. But Professor Swihart says their numbers began to decrease as more forests were cut for agriculture. Red squirrels began to spread through the state during the past century.
The researchers say red squirrels are native to forests that stay green all year, unlike walnut trees. They say the cleaning of forest land for agriculture has helped red squirrels invade Indiana. Jake Goheen calls them a sign of an environmental problem more than a cause.
【小题1】The study done by Rob Swihart and Jake Goheen is to ________.
| A．find out the living conditions for squirrels |
| B．learn squirrels’ influence on black walnut trees |
| C．do something to get rid of squirrels |
| D．save the forests in the American state of Indiana |
| A．the way they gather the walnut |
| B．the time they have winter sleep |
| C．the place they have winter sleep |
| D．the place they store the walnuts |
| A．red squirrels eat more nuts than gray squirrels |
| B．gray squirrels and red squirrels will have severe fights |
| C．nuts above the ground will not develop into plants |
| D．seeds can be traps for other animals in the forest |
| A．The black walnut is equally attractive to both gray and red squirrels. |
| B．Gray squirrels do more harm to the forest than red squirrels. |
| C．Red squirrels and gray squirrels have helped the spread of walnut trees. |
| D．The cleaning of forest land benefits red squirrels directly. |
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科目：高中英语 来源： 题型：阅读理解
Why would an animal kill itself? It seems a strange question, and yet it is one that has made some scientists curious for a long time. For there is a kind of animal called lemming（旅鼠）, that periodically killed themselves together, and no one knows just why!
The small creatures which live in the Scandinavian mountains, feed on a diet of roots and special insects and live in nests they dig underground. When their food supply is large, the lemmings live a normal and undisturbed life.
However, when the lemmings’ food supply becomes too low to support the population, a singular migration（迁徙）begins. The lemmings leave their nests in groups. Great numbers of them begin to travel across the Scandinavian plains, a journey that may last weeks. The lemmings eat everything in their path, continuing their long march until they reach the sea.
The reason for what follows remains unbelievable to naturalists. Upon reaching the coast, the lemmings do not stop but swim by the thousands into the sea. Most stay afloat only a short time before they tire, sink and drown.
A common theory for this mass self-killing is that the lemmings do not realize that the ocean is such a huge body of water in their cross-country journey, the animals must cross many smaller bodies of water, such as rivers and small lakes. They may think that the sea is just another such swimmable path to go through. But no final answer has been found to the strange happening.
【小题1】The passage is mainly about______.
| A．how lemmings find food |
| B．why animals kill themselves |
| C．the lemmings’ self-killing |
| D．the food supply in the Scandinavian mountains |
| A．go mad from a lack of food |
| B．hope to find fish for food |
| C．decide to reduce the population |
| D．think they can cross the sea |
| A．Because they are the only animals that live in Scandinavia. |
| B．Because it is very unusual for animals to kill themselves. |
| C．Because of the amount of food they can eat on their march to the sea. |
| D．Because they can gather together in such huge numbers. |
| A．unusual | B．single | C．wonderful | D．common |
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科目：高中英语 来源： 题型：阅读理解
Humans have sewn by hand for thousands of years. It was said that the first thread was made from animal muscle and sinew (肌腱). And the earliest needles were made from bones. Since those early days, many people have been involved in the process of developing a machine that could do the same thing more quickly and with greater efficiency.
Charles Wiesenthal, who was born in Germany, designed and received a patent on a double-pointed needle that eliminated the need to turn the needle around with each stitch (缝合) in England in 1755. Other inventors of that time tried to develop a functional sewing machine, but each design had at least one serious imperfection.
Frenchman Barthelemy Thimonnier finally engineered a machine that really worked. However, he was nearly killed by a group of angry tailors when they burned down his garment factory. They feared that they would lose their jobs to the machine.
American inventor Elias Howe, born on July 9, 1819, was awarded a patent for a method of sewing that used thread from two different sources. Howe’s machine had a needle with an eye at the point, and it used the two threads to make a special stitch called a lockstitch. However, Howe faced difficulty in finding buyers for his machines in America. In frustration, he traveled to England to try to sell his invention there. When he finally returned home, he found that dozens of manufacturers were adapting his discovery for use in their own sewing machines.
Isaac Singer, another American inventor, was also a manufacturer who made improvements to the design of sewing machines. He invented an up-and-down-motion mechanism that replaced the side-to-side machines. He also developed a foot treadle (脚踏板) to power his machine. This improvement left the sewer’s hands free. Undoubtedly, it was a huge improvement of the hand-cranked machine of the past. Soon the Singer sewing machine achieved more fame than the others for it was more practical. It could be adapted to home use and it could be bought on hire-purchase. The Singer sewing machine became the first home appliance, and the Singer company became one of the first American multinationals.
However, Singer used the same method to create a lockstitch that Howe had already patented. As a result, Howe accused him of patent infringement (侵犯). Of course, Elias Howe won the court case, and Singer was ordered to pay Howe royalties (版税). In the end, Howe became a millionaire, not by manufacturing the sewing machine, but by receiving royalty payments for his invention.
【小题1】Barthelemy Thimonnier’s garment factory was burned down because __________.
| A．people did not know how to put out the fire |
| B．Elias Howe thought Thimonnier had stolen his invention |
| C．the sewing machines couldn’t work finally |
| D．workers who feared the loss of their jobs to a machine set fire |
| A．Because the judge was against Singer for his unfriendly attitude. |
| B．Because Howe had already patented the lockstitch used by Singer. |
| C．Because Singer had borrowed money from Howe and never repaid it. |
| D．Because Singer and Howe had both invented the same machine. |
| A．A Stitch in Time Saves Nine |
| B．The Case between Howe and Singer |
| C．Patent Laws on the Sewing Machine |
| D．The Early History of the Sewing Machine |
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科目：高中英语 来源： 题型：阅读理解
The economic growth that many nations in Asia and increasingly Africa have experienced over the past couple of decades has transformed hundreds of millions of lives – almost entirely for the better. But there’s a byproduct to that growth, one that’s evident – or sometimes less than evident – in the smoggy, smelly skies above cities like Beijing, New Delhi and Jakarta. Thanks to new cars and power plants, air pollution is bad and getting worse in much of the world, and it’s taking a major toll (伤亡人数，代价) on global health.
How big? According to a new analysis published in the Lancet, more than 3.2 million people suffered deaths from air pollution in 2010, the largest number on record. That’s up from 800,000 in 2000. And it’s a regional problem: 65% of those deaths occurred in Asia, where the air is choked by diesel soot (内燃发动机烟雾) from cars and trucks, as well as the song from power plants and the dust from endless urban construction. In East Asia and China, 1.2 million people died, as well as another 712,000 in South Asia, including India. For the first time ever, air pollution is on the world’s top – 10 list of killers, and it’s moving up the ranks faster than any other factor.
So how can air pollution be so damaging? It is the very finest soot – so small that it roots deep within the lungs and then enters the bloodstream – that contributes to most of the public – health toll of air pollution including death. Diesel soot, which can also cause cancer, is a major problem because it is concentrated in cities along transportation zones affecting overpopulated areas. It is thought to contribute to half the deaths from air pollution in urban centers. Fro example, 1 in 6 people in the U.S. live near a diesel – pollution hot spot like a rail yard, port terminal or freeway.
We also know that air pollution may be linked to other non – deadly diseases. Fortunately in the U.S. and other developed nations, urban air is for the most part cleaner than it was 30 or 40 years ago, thanks to regulations and new technologies like the catalytic converters (催化式排气净化器) that reduce automobile emissions. Govemments are also pushing to make air cleaner – see the White House’s move last week to further tighten soot standards. It’s not perfect, but we’ve had much more success dealing with air pollution than climate change.
Will developing nations like India eventually catch up? Hopefully – though the problem may get worse before it gets better. The good news is that it doesn’t take a major technological advance to improve urban air. Switching from diesel fuel to unleaded (无铅燃油) helps, as do newer and cleaner cars which are less likely to send out pollutants. Power plants – even ones that burn mineral fuels like coal – can be fitted with pollution – control equipment that, at a price, will greatly reduce smog and other pollutants.
But the best solutions may involve urban design. In the Guardian, John Vidal notes that Delhi now has 200 cars per 1,000 people, far more than much richer Asian cities like Hong Kong and Singapore. Developing cities will almost certainly see an increase in car ownership as residents become wealthier – and that doesn’t have to mean deadly air pollution. Higher incomes should also lead to tougher environmental regulations, which is exactly what happened in the West. We can only hope it happens before the death toll from bad air gets even higher.
【小题1】What tends to give rise to the highest death toll according to the passage?
| A．The lack of tight environmental protection standards. |
| B．The increasing numbers of the diesel cars and trucks. |
| C．The frighteningly high death rate from deadly cancer. |
| D．The world’s serious air pollution such as soot and dust. |
| A．consequence | B．solution | C．reform | D．design |
| A．the diesel soot is too small to be seen |
| B．the diesel soot is much too poisonous to breathe |
| C．the diesel soot roots in lungs and gets into blood |
| D．the diesel soot can also contribute to deadly cancer |
| A．the global economic growth is mainly to blame for air pollution and climate change |
| B．the developing countries are repeating the same mistakes as the developed ones made |
| C．the ecological situation and air pollution in India are becoming worse and worse |
| D．the unbeatable air is increasingly becoming a major killer throughout the world |
| A．the making of tougher environmental regulations alone is of little use |
| B．more sever regulations should be made to handle air pollution |
| C．the urban construction in western developed countries is the best choice |
| D．the pace of development has to be slowed down to reduce air pollution |
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科目：高中英语 来源： 题型：阅读理解
In July 1994 Jupiter, the largest planet in our solar system, was struck by 21 pieces of a comet (彗星). When the fragments (碎片) landed in the southern part of the giant planet, the explosions(爆炸) were watched by scientists here on the earth. But what if our own planet was hit by a comet?
The year is 2094. It has been announced that a comet is heading towards the Earth. Most of it will miss our planet, but two fragments will probably hit the southern part of the Earth. The news has caused panic.
On 17 July, a fragment, four kilometers wide, enters the Earth's atmosphere with a huge explosion. About half of the fragment is destroyed. But the major part survives and hits the South Atlantic at 200 times the speed of sound. The sea boils and an enormous(巨大的) wave is created and spreads. The wall of water rushes towards southern Africa at 800 kilometres an hour. Cities on the African coast are totally destroyed and millions of people are drowned. The wave moves into the Indian Ocean and heads towards Asia.
Millions of people are already dead in the southern part of the Earth, but the north won't escape for long. Tons of broken pieces are thrown into the atmosphere by the explosions. As the sun is hidden by clouds of dust, temperatures around the world fall to almost zero. Crops are ruined. Wars break out as countries fight for food. A year later civilization has collapsed(崩溃). No more than 10 million people have survived.
Could it really happen? In fact, it has already happened more than once in the history of the Earth. The dinosaurs were on the Earth for over 160 million years. Then 65 million years ago they suddenly disappeared. Many scientists believe that the Earth was hit by a space fragment. The dinosaurs couldn't survive in the cold climate that followed and they became extinct. Will we meet the same end?
【小题1】Which of the following is NOT TRUE according to the author's description of the disaster in 2094?
| A．The whole world becomes extremely cold |
| B．All the coastal cities in Africa are destroyed |
| C．The visit of the comet results in wars |
| D．The whole mankind becomes extinct |
| A．Because they could only live in the warm climate |
| B．Because their extinction indicates future disasters |
| C．Because they once dominated(控制) the earth |
| D．Because dinosaurs and humans never live in the same age |
| A．give an accurate description of the possible disaster in the future |
| B．prove that humans will sooner or later be destroyed |
| C．warn of a possible disaster in the future |
| D．tell the historical development of the Earth |
| A．article of popular science | B．news report |
| C．research paper | D．horror story |
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科目：高中英语 来源： 题型：阅读理解
What exactly is intelligence? There aren’t any easy answers．Despite the progress that has been made in genetics and psychology, human intelligence has remained one of the most controversial areas of modern science，until now, that is, for the discovery of a gene linked to intelligence has made the experts think again．
Robert Plomin of the Institute of Psychiatry in London and his colleagues in the US have been looking into genetic make-up．From their research, they have discovered that a slightly different gene is more common in those with a high IQ．Plomin analyzed DNA from two groups of 51 children aged between 6 and 15．What he found was that the first group had an IQ of 136, putting them in the top 5% of the population, while the other group had an average IQ of 103．An analysis of their genes showed that 32% of children in the higher group had the gene in question, while only 16% in the second group did．However, there is a lot more research to be done, and Plomin himself is cautious at this early stage．He suggests that there are probably many genes that contribute to intelligence, rather than just one. Several studies have shown a strong link between IQ and career success, although some psychologists remain unconvinced about this．Professor Michael Rowe, who has written a book called Genius Explained, is one of these．“The people with the highest IQs are not usually the ones who do best in their careers．”
Many psychologists now believe that when it comes to intelligence, IQ isn’t everything．Many alternative views have been put forward recently．One example is the idea of multiple intelligences, which was developed in the 1980s by Harvard psychologist Howard Gardner．This offers a much broader view than the IQ theory, including creativity and communication skills as relevant factors in intelligence．
Tony Buzan, brain expert and author of Master your Memory, is enthusiastic about this belief, arguing that true geniuses do indeed appear to combine high levels of each type of intelligence．He lists Alexander the Great, Pablo Picasso and Albert Einstein as examples．At the same time, Buzan believes that everyone can develop their intelligence, only if they take the trouble to exercise their brain．Perhaps there’s hope for us all!
【小题1】What does the underlined word “This” in Paragraph 3 refer to?
| A．The development of intelligence |
| B．The idea of multiple intelligences |
| C．IQ isn’t everything for intelligence |
| D．Alternative views have been put forward |
| A．To make a suggestion． | B．To draw a conclusion |
| C．To prove an idea． | D．To give an example |
| A．Robert Plomin confirms genes have something in common |
| B．Howard Gardner thinks intelligence includes various factors |
| C．Michael Rowe approves of a strong link between IQ and career |
| D．Tony Buzan agrees geniuses exercise brain to improve intelligence |
| A．The relationship between genes and intelligence |
| B．IQ benefits a lot from high intelligence |
| C．How to develop intelligence． |
| D．What makes intelligence. |
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科目：高中英语 来源： 题型：阅读理解
Many businesses today use conferences as a means of discussing new plans of the company. As people are paying more attention to the environment and green problems, more businesses are looking for ways to reduce their negative effect on the environment. Many businesses do this by using web conferencing.
Web conferencing is a technology that allows people to communicate more effectively over the Internet. It is an easy way of hosting and attending conferences without having to leave the office. Each of the people involved in a web conference will be posted an invitation to the conference with the time and date of the Web conference on it. When the conference is ready to begin, all participants (参与者) must sit at their computers and they will be connected over the Internet.
With Web conferencing all participants attend the conference from the comfort of their own desk. Obviously, in doing this no fuel is used in traveling to and from a conference, and less work time is taken up in attending a conference.
Any material to be used during the Web conference is simply e-mailed to all the participants before the conference. Participants can then either choose to print material or read it on screen. This not only saves paper but also greatly reduces mailing cost for the business.
As a conference hall or business center isn’t being used, it means that the only power that is used is the power used by the participants’ personal computers. Similarly conference organizers don’t have to arrange for food or overnight accommodation (住宿) for participants of their conferences. All this means that less energy is used.
Often in business some companies actively choose to do business with other companies that do many things to reduce their negative impact on the environment. And Web conferencing helps you show other businesses that you are willing to work hard for the green cause.
So Web conferencing is much cheaper and greener and more people are willing to host and attend a web conference.
【小题1】What is the passage mainly about?
A. Ways of protecting the environment.
B. B. Green benefits of Web conference.
C. Ways of hosting a Web conference.
D. Impacts of Web conferencing on costs.
【小题2】According to paragraph 1, many companies use Web conferencing because they ________.
| A．are interested in using any new technology |
| B．believe that Web conferencing is more convenient |
| C．want to do something to protect the environment |
| D．haven’t enough money to hold a traditional conference |
| A．will be e-mailed an invitation before the conference |
| B．are required to sit in the office together |
| C．will receive many paper materials |
| D．must have access to the Internet |
| A．Useless. | B．Environmentally friendly. |
| C．Inconvenient. | D．Money-consuming. |
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