Canpeoplechangetheirskincolour

更新 2022-09-03
科目英语
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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.
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

We can infer from the passage that .

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

Which of the following is NOT mentioned according to the passage?

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.

The passage is probably taken from __________.

A．a novel	B．a science report
C．a story book	D．a science fiction

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This is a dangerous world we live in. The numbers of murders goes up every year； people are dying of cancer；more people contract（感染）HIV；more teens are using drugs；etc. You know this because you’ve heard all the statistics on the news. But do you really have an accurate idea what they mean? The numbers are going up, but how do they compare to the growth in population? Are more cases of these diseases being reported because of better testing techniques, or are the diseases more common? The fact is that without knowing the background, statistics mean very little.
This growing trend of reporting only part of the information is becoming dangerous.
For example, several years ago a high school student reported dangers of the chemical known as dihydrogen monoxide. This chemical, found in most cancerous tumors（肿瘤）， is found in the blood of people drunk on alcohol, and causes complete physical and mental dependence for those who take the chemical even once. After reading his report, more than 75% of his Advanced Placement Chemistry class voted to forbid this dangerous chemical! Every one of the above statements is true, yet this chemical is necessary to all life on earth. The students made the mistake because they voted knowing only a few statements and statistics, rather than the chemical’s full background.
The point of this article is that one should be aware of what is and is not being said. When one finds a new fact or number, one should try to consider other important information before forming an opinion with only half-truths. Always remember that the author is trying to convince you of his or her own view, and will leave out information that is different to his view. For example, look again at the statistics that suggest skiing is safe. Only 32 people may die each year when skiing, while 897 die from lightning strikes, but which is really more dangerous? If you think about it, you will realize far fewer people go skiing each year than the number of people who are in danger of a lightening strike. When you think about it, skiing is more dangerous than you might at first think when looking at statistics. If we teenagers are to be left in this world, we had better be able think critically, and form our own views. rather than be easily persuaded by another’s. To be warned is to be prepared.
59．In the first paragraph, what problem does the writer want to warn us?
A. We are now living in a dangerous world.
B. We got a lot of false statistics from the media.
C. There are around us more and more murders, diseases etc.
D. Statistics alone without full background don’t give us an accurate picture of things.
60．Why does the writer use the example in the second paragraph?
A. To show the danger of reporting only part of the information.
B. To argue that high school students are easily persuaded.
C. To prove what is necessary to us might be dangerous.
D. To warn us of the harmful substances（物质）around us.
61．Relative information is often left out because .
A. relative information is not that important
B. the author is trying to show what he or she says is true
C. too much information will make readers feel confused
D. readers are not able to analyze so much information at once
62．What is the main idea of this passage?
A. Some measures must be taken to protect our dangerous world.
B. We should learn to think critically and look at problems from all sides.
C. The growing trend of reporting only half-truths is getting out of control.
D. Teenagers ought to improve their ability of telling right from wrong.

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The first thing my host father “warmed” me was that almost everyone in America was a big hugger.
I didn’t understand what he meant until my first party. Whether they were friends or strangers, teenagers or elders, girls or guys, everyone I met gave me a big hug.
However, as time went on, I began to understand America’s hugging culture. When a friend broke up with me, I was sad. When I told my best American friend about it, she said nothing but put her arms around me. Then warmth of the hug was a greater comfort than anything she could have said to me.
One winter day I was walking along the street, shivering（颤抖）. It was then I saw two women, each holding a paper board, on which there were two words：FREE HUGS. Their were red because of the freezing weather and they were jumping up and down to keep themselves warm. “Hi, girl! Do you want a hug?” One of them asked me. I went up and opened my arms. The hug was short but warm and it took some of the coldness of the day away.
After that I became a big hugger myself. One time my host father and I were traveling to another town. When we reached a restaurant where my friend Cindy worked, he stopped the car.
“What’ wrong?” I asked.” “Alice, why don’t you go inside and give Cindy a hug?” He suggested. I went into the restaurant, ran straight up to Cindy, and gave her a hug before she realized what was going on. “That was a big surprise! And you got my day sweetie! ” She told me later.
A hug is a way to communicate love and care. Do you want a hug? My arms are wide open.
56．The point of the first three paragraphs is to explain      .
A．how body language is more important than actual words
B．why hugging is so important in American culture
C．how expressing, feelings can be difficult for Chinese
D．how the author’s attitude toward hugging culture changed
57．We can infer from the passage that the host father      .
A．seldom has has time to spend with the author
B．often shares his experience with the author
C．warns the author of the possible danger
D．teachers the author to show her care for her friends
58．According the passage, a hug can make us feel
A．comforted, loved and cared for                   B．happy, understood and amazed
C．excited, wise and surprised     D．cared for, wise and happy

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    Who’s in control of your life? Who is pulling your string? For the majority of us, it’s other people – society, colleagues, friends, family or our religious community. We learned this way of operating when we were very young, of course．We were brainwashed．We discovered that feeling important and feeling accepted was a nice experience and so we learned to do everything we could to make other people like us．As Oscar Wilde puts it，“Most people are other people．Their thoughts are someone else’s opinions，their lives a mimicry(模仿)，their passions a quotation．”
So when people tell us how wonderful we are，it makes us feel good．We long for this good feeling like a drug—we are addicted to it and seek it out wherever we can．Therefore，we are so eager for the approval of others that we live unhappy and limited lives，failing to do the things we really want to．Just as drug addicts and alcoholics live worsened lives to keep getting theirfix(一剂毒品)，we worsen our own existence to get our own constant fix of approval．
But just as with any drug，there is a price to pay．The price of the approval drug is freedom--the freedom to be ourselves. The truth is that we cannot control what other people think．People have their own agenda，and they come with their own baggage and，in the end，they’re more interested in themselves than in you．Furthermore，if we try to live by the opinions of others，we will build our life on sinking sand．Everyone has a different way of thinking，and people change their opinions all the time．The person who tries to please everyone will only end up getting exhausted and probably pleasing no one in the process．
So how can we take back control? I think there’s only one way--make a conscious decision to stop caring what other people think．We should guide ourselves by means of a set of values—not values imposed from the outside by others，but innate values which come from within．If we are driven by these values and not by the changing opinions and value systems of others，we will live a more authentic，effective，purposeful and happy life．
67．What Oscar Wilde says implies that        ．
A．we have thoughts similar to those of others
B．most people have a variety of thoughts
C．other people’s thoughts are more important
D．most people’s thoughts are controlled by others
68．What does the author try to argue in the third paragraph?
A．Changing opinions may cost us our freedom．
B．We may lose ourselves to please others．
C．We need to pay for what we want to get．
D．The price of taking the drug is freedom．
69．It can be concluded from the passage that         ．
A. it’s better to do what we like
B．we shouldn’t care what others think
C．we shouldn’t change our own opinions
D．it's important to accept others’ opinions
70．The author tries to persuade the readers to accept his arguments mainly by      .
A．analyzing causes and effects
B．providing examples and facts
C．discussing questions
D．making suggestions

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   An Australian company, Smart Car Technologies, has developed a system that lets drivers know when they're speeding. When the technology becomes commercially available, it could help lead-footed drivers avoid tickets and also save lives. The company that developed the product hopes to convince Australian government agencies to put the technology into use in their automobile fleets.
The product, called Speed Alert, links real-time location data and speed obtained with the help of GPS to a database of posted speed limits stored in a driver's PDA or programmable mobile phone. The setup of the product does not need to be hooked up to a car's speedometer. In fact, it is entirely portable. It will also work with newer phones and PDAs that have built-in GPS receivers. If a driver exceeds the speed limit, the speed is shown and an alert sounds.
Michael Paine, an Australian vehicle design engineer and traffic safety consultant, was hired to analyze the product. He told Live Science that his colleagues in the road safety field are “very enthusiastic” about what they're now calling “intelligent speed alert.” Other research, according to Paine, shows that 40 percent of all traffic deaths involve speeding. There is also a potentially controversial future use: “Since the system is so portable, it would be easy to make it a requirement for teenage drivers to always use a speed alert device when driving,” Paine said. “The system even has the capability to record speeding violations, so parents can monitor their teenage drivers.”The product will soon go on sale in Sydney.
63．What's the purpose of the new product?
A．To introduce some improvement in cars.
B．To inform us of the new car system.
C．To popularize the built-in car system.
D．To limit certain drivers to safe driving.
64．“Lead-footed” in the first paragraph probably refer to the ones ________.
A．who drive too carelessly   B．that drive too slowly
C．who are partly disabled     D．that drive extremely fast
65．The second paragraph mainly talks about ________.
A．how the product is programmed       B．why the system becomes popular
C．the functions of GPS in cars       D．the project of the built-in product
66．Which of the following would be the best title for the passage?
A．Future Speed Alert    B．New In – Car Device Against Speeding
C．Warning for Adventurous Drivers     D．Progress in Car – making Science

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In February 2010, Lydia Angyiou and her two sons were walking through their village in northern Canada. The sound of children shouting made her turn around. To her horror, Lydia saw a 700 – pound polar bear behind her eyeing her seven-year-old son．Getting between the bear and her child, Lydia yelled at the children to run away．She then began hitting and kicking the animal as hard as she could．A neighbor who heard all the noise came and shot the bear．But everyone agreed it was Lydia who had saved her children's lives．A local policeman described it this way: "I guess when your back is up against the wall, we come up with super-human strength."
Where does this "super-human strength" , courage and quick thinking come from? Experts say it comes from stress! In stressful situations, the body releases chemicals that prepare it to take action．These chemicals give people the speed and strength they need to fight danger or run away from it．
When we think of stress, we usually think of its negative effects．Studies, though, show that moderate levels of stress are actually helpful．In fact, the way we perform is usually affected by the amount of stress we feel．Stress causes the brain to release adrenaline （肾上腺素）which in turn increases our energy and excitement．The chemical gives us clearer minds and helps us to do more．This is why some people say they work better under a deadline．Adrenaline that is not released for long periods of time can cause us to be bored and lazy. So some stress actually increases and strengthens our abilities instead of weakening them. We sometimes turn out our very best work when we push ourselves to the limit．Stress can also make us more confident．Handling small amounts of stress now prepares us for handling serious situations in the future．Who knows? Today's stress may even prepare us for the next polar bear that comes along!
60．The author mentions the story of the mother and her children mainly to         .
A．tell people females also have enough strength to fight with a bear
B．show us how much the mother loves her children
C．set an example to us about how to deal with danger
D．illustrate to us stressful situations can make us stronger
61．What does the word “it” underlined in the second paragraph refer to?
A．released chemical               B．the body
C．stress                  D．strength
62．What will the author probably continue to write in the paragraph that follows?
A．How to deal with a bear when you meet with it unfortunately.
B．Why we need small stress in life.
C．Tips for a person to develop his ability of dealing with stress.
D．When the brain releases adrenaline.

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