剑桥雅思官方范文(通用十篇)

山崖发表网范文2022-08-28 08:51:20309

剑桥雅思官方范文(篇一)

The charts below show the results of a survey of adult education. The first chart shows the reasons why adults decide to study. The pie chart shows how people think the costs of adult education should be a report for a university lecturer, describing the information shown at least 150 Words.

Model Answer:

The summary of a survey on adult education is presented in the 2 charts. The bar chart summarizes the factors that caused adults to continue their education, while the pie chart shows the public opinion regarding the funding of adult education.

According to the bar chart, 40% of the respondents mentioned “interest in the subject” as the reason they decided to go back to school. This factor was followed closely by the aim to gain qualification at 38%. On the other hand, only 9% of the survey participants said that they went to school in order to meet more people. This is the least popular reason among the 7 given.

Among all the people surveyed regarding the funding, 40% of them felt that this adult education should be the responsibility of the individual. Although 35% of them thought that the employers should lend the helping hand, only 25% agreed that the taxpayers should share the burden.

In summary, the survey showed a mixed opinion regarding the reasons and the funding for adults education.

剑桥雅思官方范文(篇二)

The chart gives information about post-school qualifications in terms of the different levels of further education reached by men and women in Australia in 1999.

We can see immediately that there were substantial differences in the proportion of men and women at different levels. The biggest gender difference is at the lowest post-school level, where 90% of those who held a skilled vocational diploma were men, compared with only 10% of women. This article is from Laokaoya website. By contrast, more women held undergraduate diplomas (70%) and marginally more women reached degree level (55%).

At the higher levels of education, men with postgraduate diplomas clearly outnumbered their female counterparts (70% and 30%, respectively), and also constituted 60% of Master’s graduates.

Thus we can see that more men than women hold qualifications at the lower and higher levels of education, while more women reach undergraduate diploma level than men. The gender difference is smallest at the level of Bachelor’s degree, however.

剑桥雅思官方范文(篇三)

Task:More people are using mobile phones and computers to communicate. Therefore, people are losing the ability to communicate with each other face to face. To what extent do you agree or disagree?

Sample answer:

Now you are benefiting from the use of mobile phone and the Internet as social interaction media, could you imagine what your daily lives would be without these inventions? Some people claim that individuals are gradually losing face-to-face communication skills. Nevertheless, from personal perspective, online communication cannot make people lose the ability of offline communication.

Apparently, excessive use of the Internet and mobile phones has been undermining our interpersonal relationship offline. Even during a face-to-face conversation, it is no rare thing that everyone is busy looking at his cell phones, neglecting his friends or families across the dinner table. In addition, it has become incredibly easy to contact each other electronically and share information instantly in social community. Gone are the days when people could only communicate via fixed telephone or writing letters which took several days to reach others. So no one is not crazy about smart phones and computers which boast cutting-edge functions like sharing photos and videos with more friends simultaneously.

In spite of the popularity of technological progress mentioned above, never should we turn a blind eye to the irreplaceablity of face-to-face communication. It is common that many schools impart knowledge to students by teaching in classrooms instead of distance education. The same is true of the cooperation among companies, which needs face to face conversation to acquire trust with each other in advance. Furthermore, although online contact may possess increasing numbers of friends, the permanence of mutual relationships cannot lack face-to-face interactions, which can be confirmed by the example of the closest friends and even loving couples. Besides, solving tricky issues are generally more effective and more convenient by surrounding colleagues or friends then by those who live and work in remote places and need online communication.

As far as social interaction is concerned, although the cell phone and the Internet have updated the lives of the current generation. People cannot forget how to make offline communication with each other.

剑桥雅思官方范文(篇四)

The information given by the line chart is about the percentage of people aged 65 and over from 1940 to 2040 in three different nations (namely, Japan, Sweden and USA).

As we can see from the three-line chart, in 1940, USA had the largest proportion of elderly people aged 65 and more, taking up nearly to 10%. It increased to 15% during the next four decades, which was closely followed by a leveling off at 14% for nearly 20 years. However, it is estimated to see a dramatic increase to just under 25% in 2040. Similarly, the proportion of old people in Sweden was always lower than that of USA. But, it exceeded the percentage of old people in USA in 1995 and it is expected to hit 25% in 2040, although there will be some fluctuations.

On the contrary, the proportion of people aged 65 and more in Japan saw a decrease from 5% in 1940 to about 3% in 1960 and it kept stable for over 20 years. Interesting, it is expected to grow dramatically and exceed that of Sweden and USA, shooting just over 25% in 2040, becoming the country which will house the most percentage of elderly people.

All in all, it is clear to see that there was and will be a clear difference in the proportion of elderly people aged 65 and more in the three countries.

剑桥雅思官方范文(篇五)

A problem of modern societies is the declining level of health in the general population, with conflicting views on how to tackle this worrying trend. One possible solution is to provide more sports facilities to encourage a more active lifestyle.

Advocates of this believe that today’s sedentary lifestyle and stressful working conditions mean that physical activity is no longer part of either our work or our leisure time. If there were easy-to-reach local sports centres, we would be more likely to make exercise a regular part of our lives, rather than just collapsing in front of a screen every evening. The variety of sports that could be offered would cater for all ages, levels of fitness and interests: those with painful memories of PE at school might be happier in the swimming pool than on the football pitch.

However, there may be better ways of tackling this problem. Interest in sport is not universal, and additional facilities might attract the already fit, not those who most need them. Physical activity could be encouraged relatively cheaply, for example by installing exercise equipment in parks, as my local council has done. This has the added benefit that parents and children often use them together just for fun, which develops a positive attitude to exercise at an early age.

As well as physical activity, high tax penalties could be imposed on high-fat food products, tobacco and alcohol, as excessive consumption of any of these contributions to poor health. Even improving public transport would help: it takes longer to walk to the bus stop than the car.

In my opinion, focusing on sports facilities is too narrow an approach and would not have the desired results. People should be encouraged not only to be more physically active but also to adopt a healthier lifestyle in general.

剑桥雅思官方范文(篇六)

READING PASSAGE 1

You should spend about 20 minutes on Questions 1-13, which are based on Reading Passage 1 below.

AUSTRALIA’S SPORTING SUCCESS

A They play hard, they play often, and they play to win. Australian sports teams win more than their fair share of titles, demolishing rivals with seeming ease. How do they do it? A big part of the secret is an extensive and expensive network of sporting academies underpinned by science and medicine. At the Australian Institute of Sport (AIS), hundreds of youngsters and pros live and train under the eyes of coaches. Another body, the Australian Sports Commission (ASC), finances programmes of excellence in a total of 96 sports for thousands of sportsmen and women. Both provide intensive coaching, training facilities and nutritional advice.

B Inside the academies, science takes centre stage. The AIS employs more than 100 sports scientists and doctors, and collaborates with scores of others in universities and research centres. AIS scientists work across a number of sports, applying skills learned in one — such as building muscle strength in golfers — to others, such as swimming and squash. They are backed up by technicians who design instruments to collect data from athletes. They all focus on one aim: winning. ‘We can’t waste our time looking at ethereal scientific questions that don’t help the coach work with an athlete and improve performance,’ says Peter Fricker, chief of science at AIS.

C A lot of their work comes down to measurement — everything from the exact angle of a swimmer’s dive to the second-by-second power output of a cyclist. This data is used to wring improvements out of athletes. The focus is on individuals, tweaking performances to squeeze an extra hundredth of a second here, an extra millimetre there. No gain is too slight to bother with. It’s the tiny, gradual improvements that add up to world-beating results. To demonstrate how the system works, Bruce Mason at AIS shows off the prototype of a 3D analysis tool for studying swimmers. A wire-frame model of a champion swimmer slices through the water, her arms moving in slow motion. Looking side-on, Mason measures the distance between strokes. From above, he analyses how her spine swivels. When fully developed, this system will enable him to build a biomechanical profile for coaches to use to help budding swimmers. Mason’s contribution to sport also includes the development of the SWAN (Swimming Analysis) system now used in Australian national competitions. It collects images from digital cameras running at 50 frames a second and breaks down each part of a swimmer’s performance into factors that can be analysed individually — stroke length, stroke frequency, average duration of each stroke, velocity, start, lap and finish times, and so on. At the end of each race, SWAN spits out data on each swimmer.

D ‘Take a look,’ says Mason, pulling out a sheet of data. He points out the data on the swimmers in second and third place, which shows that the one who finished third actually swam faster. So why did he finish 35 hundredths of a second down? ‘His turn times were 44 hundredths of a second behind the other guy,’ says Mason. ‘If he can improve on his turns, he can do much better.’ This is the kind of accuracy that AIS scientists’ research is bringing to a range of sports. With the Cooperative Research Centre for Micro Technology in Melbourne, they are developing unobtrusive sensors that will be embedded in an athlete’s clothes or running shoes to monitor heart rate, sweating, heat production or any other factor that might have an impact on an athlete’s ability to run. There’s more to it than simply measuring performance. Fricker gives the example of athletes who may be down with coughs and colds 11 or 12 times a year. After years of experimentation, AIS and the University of Newcastle in New South Wales developed a test that measures how much of the immune-system protein immunoglobulin A is present in athletes’ saliva. If IgA levels suddenly fall below a certain level, training is eased or dropped altogether. Soon, IgA levels start rising again, and the danger passes. Since the tests were introduced, AIS athletes in all sports have been remarkably successful at staying healthy.

E Using data is a complex business. Well before a championship, sports scientists and coaches start to prepare the athlete by developing a ‘competition model’, based on what they expect will be the winning times.’ You design the model to make that time,’ says Mason.’ A start of this much, each free-swimming period has to be this fast, with a certain stroke frequency and stroke length, with turns done in these times.’ All the training is then geared towards making the athlete hit those targets, both overall and for each segment of the race. Techniques like these have transformed Australia into arguably the world’s most successful sporting nation.

F Of course, there’s nothing to stop other countries copying — and many have tried. Some years ago, the AIS unveiled coolant-lined jackets for endurance athletes. At the Atlanta Olympic Games in 1996, these sliced as much as two per cent off cyclists’ and rowers’ times. Now everyone uses them. The same has happened to the ‘altitude tent’, developed by AIS to replicate the effect of altitude training at sea level. But Australia’s success story is about more than easily copied technological fixes, and up to now no nation has replicated its all-encompassing system.

Questions 1-7

Reading Passage 1 has six paragraphs, A-F.

Which paragraph contains the following information?

Write the correct letter, A-F, in boxes 1-7 on your answer sheet.

NB You may use any letter more than once.

1 a reference to the exchange of expertise between different sports

2 an explanation of how visual imaging is employed in investigations

3 a reason for narrowing the scope of research activity

4 how some AIS ideas have been reproduced

5 how obstacles to optimum achievement can be investigated

6 an overview of the funded support of athletes

7 how performance requirements are calculated before an event

Questions 8-11

Classify the following techniques according to whether the writer states they

A are currently exclusively used by Australians

B will be used in the future by Australians

C are currently used by both Australians and their rivals

Write the correct letter, A, B or C, in boxes 8-11 on your answer sheet.

8 cameras

9 sensors

10 protein tests

11 altitude tents

Questions 12 and 13

Answer the questions below.

Choose NO MORE THAN THREE WORDS ANDIOR A NUMBER from the passage for each answer.

Write your answers in boxes 12 and 13 on your answer sheet.

12 What is produced to help an athlete plan their performance in an event?

13 By how much did some cyclists’ performance improve at the 1996 Olympic Games?

READING PASSAGE 2

You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 below.

DELIVERING THE GOODS

The vast expansion in international trade owes much to a revolution in the business of moving freight

A International trade is growing at a startling pace. While the global economy has been expanding at a bit over 3% a year, the volume of trade has been rising at a compound annual rate of about twice that. Foreign products, from meat to machinery, play a more important role in almost every economy in the world, and foreign markets now tempt businesses that never much worried about sales beyond their nation’s borders.

B What lies behind this explosion in international commerce? The general worldwide decline in trade barriers, such as customs duties and import quotas, is surely one explanation. The economic opening of countries that have traditionally been minor players is another. But one force behind the import-export boom has passed all but unnoticed: the rapidly falling cost of getting goods to market. Theoretically, in the world of trade, shipping costs do not matter. Goods, once they have been made, are assumed to move instantly and at no cost from place to place. The real world, however, is full of frictions. Cheap labour may make Chinese clothing competitive in America, but if delays in shipment tie up working capital and cause winter coats to arrive in spring, trade may lose its advantages.

C At the turn of the 20th century, agriculture and manufacturing were the two most important sectors almost everywhere, accounting for about 70% of total output in Germany, Italy and France, and 40-50% in America, Britain and Japan. International commerce was therefore dominated by raw materials, such as wheat, wood and iron ore, or processed commodities, such as meat and steel. But these sorts of products are heavy and bulky and the cost of transporting them relatively high.

D Countries still trade disproportionately with their geographic neighbours. Over time, however, world output has shifted into goods whose worth is unrelated to their size and weight. Today, it is finished manufactured products that dominate the flow of trade, and, thanks to technological advances such as lightweight components, manufactured goods themselves have tended to become lighter and less bulky. As a result, less transportation is required for every dollar’s worth of imports or exports.

E To see how this influences trade, consider the business of making disk drives for computers. Most of the world’s disk-drive manufacturing is concentrated in South-east Asia. This is possible only because disk drives, while valuable, are small and light and so cost little to ship. Computer manufacturers in Japan or Texas will not face hugely bigger freight bills if they import drives from Singapore rather than purchasing them on the domestic market. Distance therefore poses no obstacle to the globalisation of the disk-drive industry.

F This is even more true of the fast-growing information industries. Films and compact discs cost little to transport, even by aeroplane. Computer software can be ‘exported’ without ever loading it onto a ship, simply by transmitting it over telephone lines from one country to another, so freight rates and cargo-handling schedules become insignificant factors in deciding where to make the product. Businesses can locate based on other considerations, such as the availability of labour, while worrying less about the cost of delivering their output.

G In many countries deregulation has helped to drive the process along. But, behind the scenes, a series of technological innovations known broadly as containerisation and inter-modal transportation has led to swift productivity improvements in cargo-handling. Forty years ago, the process of exporting or importing involved a great many stages of handling, which risked portions of the shipment being damaged or stolen along the way. The invention of the container crane made it possible to load and unload containers without capsizing the ship and the adoption of standard container sizes allowed almost any box to be transported on any ship. By 1967, dual-purpose ships, carrying loose cargo in the hold_and containers on the deck, were giving way to all-container vessels that moved thousands of boxes at a time.

H The shipping container transformed ocean shipping into a highly efficient, intensely competitive business. But getting the cargo to and from the dock was a different story. National governments, by and large, kept a much firmer hand on truck and railroad tariffs than on charges for ocean freight. This started changing, however, in the mid-1970s, when America began to deregulate its transportation industry. First airlines, then road hauliers and railways, were freed from restrictions on what they could carry, where they could haul it and what price they could charge. Big productivity gains resulted. Between 1985 and 1996, for example, America’s freight railways dramatically reduced their employment, trackage, and their fleets of locomotives — while increasing the amount of cargo they hauled. Europe’s railways have also shown marked, albeit smaller, productivity improvements.

I In America the period of huge productivity gains in transportation may be almost over, but in most countries the process still has far to go. State ownership of railways and airlines, regulation of freight rates and toleration of anti-competitive practices, such as cargo-handling monopolies, all keep the cost of shipping unnecessarily high and deter international trade. Bringing these barriers down would help the world’s economies grow even closer.

hold: ship’s storage area below beck

Questions 14-17

Reading Passage 2 has nine paragraphs, A-I.

Which paragraph contains the following information?

Write the correct letter, A-I, in boxes 14-17 on your answer sheet.

14 a suggestion for improving trade in the future

15 the effects of the introduction of electronic delivery

16 the similar cost involved in transporting a product from abroad or from a local supplier

17 the weakening relationship between the value of goods and the cost of their delivery

Questions 18-22

Do the following statements agree with the information given in Reading Passage 2?

In boxes 18-22 on your answer sheet, write

TRUE if the statement agrees with the information

FALSE if the statement contradicts the information

NOT GIVEN if there is no information on this

18 International trade is increasing at a greater rate than the world economy.

19 Cheap labour guarantees effective trade conditions.

20 Japan imports more meat and steel than France.

21 Most countries continue to prefer to trade with nearby nations.

22 Small computer components are manufactured in Germany.

Questions 23-26

Complete the summary using the list of words, A-K, below.

Write the correct letter, A-K, in boxes 23-26 on your answer sheet.

THE TRANSPORT REVOLUTION

Modern Cargo-handing methods have had a significant effect on 23............ as the business of moving freight around the world becomes increasingly streamlined.

Manufacturers of computers, for instance, are able to import 24............ from overseas, rather than having to rely on a local supplier. The introduction of 25............ has meant that bulk cargo can be safely and efficiently moved over long distances. While international shipping is now efficient, there is still a need for governments to reduce 26............: in order to free up the domestic cargo sector.

A tariffs B components C container ships

D output E employees F insurance costs

G trade H freight I fares

J software K international standards

READING PASSAGE 3

You should spend about 20 minutes on Questions 27-40, which are based on Reading Passage 3 on the following pages.

Question 27-32

Reading Passage 3 has seven paragraphs, A-G.

Choose the correct heading for paragraphs B-G from the list of headings below.

Write the correct number, i-ix, in boxes 27-32 on you answer sheet.

List of Headings

i The reaction of the Inuit community to climate change

ii Understanding of climate change remains limited

iii Alternative sources of essential supplies

iv Respect for Inuit opinion grows

v A healthier choice of food

vi A difficult landscape

vii Negative effects on well-being

viii Alarm caused by unprecedented events in the Arctic

ix The benefits of an easier existence

Example Answer

Paragraph A viii

27 Paragraph B

28 Paragraph C

29 Paragraph D

30 Paragraph E

31 Paragraph F

32 Paragraph G

Climate Change and the Inuit

The threat posed by climate change in the Arctic and the problems faced by Canada’s Inuit people

A Unusual incidents are being reported across the Arctic. Inuit families going off on snowmobiles to prepare their summer hunting camps have found themselves cut off from home by a sea of mud, following early thaws. There are reports of igloos losing their insulating properties as the snow drips and refreezes, of lakes draining into the sea as permafrost melts, and sea ice breaking up earlier than usual, carrying seals beyond the reach of hunters. Climate change may still be a rather abstract idea to most of us, but in the Arctic it is already having dramatic effects — if summertime ice continues to shrink at its present rate, the Arctic Ocean could soon become virtually ice-free in summer. The knock-on effects are likely to include more warming, cloudier skies, increased precipitation and higher sea levels. Scientists are increasingly keen to find out what’s going on because they consider the Arctic the ‘canary in the mine’ for global warming — a warning of what’s in store for the rest of the world.

B For the Inuit the problem is urgent. They live in precarious balance with one of the toughest environments on earth. Climate change, whatever its causes, is a direct threat to their way of life. Nobody knows the Arctic as well as the locals, which is why they are not content simply to stand back and let outside experts tell them what’s happening. In Canada, where the Inuit people are jealously guarding their hard-won autonomy in the country’s newest territory, Nunavut, they believe their best hope of survival in this changing environment lies in combining their ancestral knowledge with the best of modern science. This is a challenge in itself.

C The Canadian Arctic is a vast, treeless polar desert that’s covered with snow for most of the year. Venture into this terrain and you get some idea of the hardships facing anyone who calls this home. Farming is out of the question and nature offers meagre pickings. Humans first settled in the Arctic a mere 4,500 years ago, surviving by exploiting sea mammals and fish. The environment tested them to the limits: sometimes the colonists were successful, sometimes they failed and vanished. But around a thousand years ago, one group emerged that was uniquely well adapted to cope with the Arctic environment. These Thule people moved in from Alaska, bringing kayaks, sleds, dogs, pottery and iron tools. They are the ancestors of today’s Inuit people.

D Life for the descendants of the Thule people is still harsh. Nunavut is million square kilometres of rock and ice, and a handful of islands around the North Pole. It’s currently home to 2,500 people, all but a handful of them indigenous Inuit. Over the past 40 years, most have abandoned their nomadic ways and settled in the territory’s 28 isolated communities, but they still rely heavily on nature to provide food and clothing. Provisions available in local shops have to be flown into Nunavut on one of the most costly air networks in the world, or brought by supply ship during the few ice-free weeks of summer. It would cost a family around £7,000 a year to replace meat they obtained themselves through hunting with imported meat. Economic opportunities are scarce, and for many people state benefits are their only income.

E While the Inuit may not actually starve if hunting and trapping are curtailed by climate change, there has certainly been an impact on people’s health. Obesity, heart disease and diabetes are beginning to appear in a people for whom these have never before been problems. There has been a crisis of identity as the traditional skills of hunting, trapping and preparing skins have begun to disappear. In Nunavut’s ‘igloo and email’ society, where adults who were born in igloos have children who may never have been out on the land, there’s a high incidence of depression.

F With so much at stake, the Inuit are determined to play a key role in teasing out the mysteries of climate change in the Arctic. Having survived there for centuries, they believe their wealth of traditional knowledge is vital to the task. And Western scientists are starting to draw on this wisdom, increasingly referred to as ‘Intelligence Quotient’, or IQ. ‘In the early days scientists ignored us when they came up here to study anything. They just figured these people don’t know very much so we won’t ask them,’ says John Amagoalik, an Inuit leader and politician. ‘But in recent years IQ has had much more credibility and weight.’ In fact it is now a requirement for anyone hoping to get permission to do research that they consult the communities, who are helping to set the research agenda to reflect their most important concerns. They can turn down applications from scientists they believe will work against their interests, or research projects that will impinge too much on their daily lives and traditional activities.

G Some scientists doubt the value of traditional knowledge because the occupation of the Arctic doesn’t go back far enough. Others, however, point out that the first weather stations in the far north date back just 50 years. There are still huge gaps in our environmental knowledge, and despite the scientific onslaught, many predictions are no more than best guesses. IQ could help to bridge the gap and resolve the tremendous uncertainty about how much of what we’re seeing is natural capriciousness and how much is the consequence of human activity.

Questions 33-40

Complete the summary of paragraphs C and D below.

Choose NO MORE THAN TWO WORDS from paragraphs C and D for each answer.

Write you answers in boxes 33-40 on your answer sheet.

If you visit the Canadian Arctic, you immediately appreciate the problems faced by people for whom this is home. It would clearly be impossible for the people to engage in 33............... as a means of supporting themselves. For thousands of years they have had to rely on catching 34...............and 35...............as a means of sustenance. The harsh surroundings saw many who tried to settle there pushed to their limits, although some were successful. The 36...............people were an example of the latter and for them the environment did not prove unmanageable. For the present inhabitants, life continues to be a struggle. The territory of Nunavut consists of little more than ice, rock and a few 37............... . In recent years, many of them have been obliged to give up their 38............... lifestyle, but they continue to depend mainly on 39............... for their food and clothes. 40...............produce is particularly expensive.

剑桥雅思官方范文(篇七)

This bar chart analyzes the percentage of household waste recycled from 1992 to 2002. We can see that the percentage during 2002 increased all the way while other years fluctuated. In the various materials, paper and glass are the ones that with greater percentage that was recycled. In contrast, the plastic and cans had a lower percentage.

From the graph we can see that during 1992 cans have the highest percentage about 17% and plastic has the lowest at about 10%. After that, in year 1997, paper and glass became major types of waste that were recycled, at about 31% and 29% respectively. In 2002, glass became the dominant type of waste that was recycled with about 48%. Meanwhile, plastic had grown least around 2% and glass had grown the most around 34% in these 10 years, and paper chasing behind with 26%. Cans were more stable, with ony about 6% total growth.

剑桥雅思官方范文(篇八)

Research using twins

To biomedical researchers all over the world, twins offer a precious opportunity to untangle the influence of genes and the environment — of nature and nurture. Because identical twins come from a single fertilized egg that splits into two, they share virtually the same genetic code. Any differences between them — one twin having younger looking skin, for example — must be due to environmental factors such as less time spent in the sun.

Alternatively, by comparing the experiences of identical twins with those of fraternal twins, who come from separate eggs and share on average half their DNA, researchers can quantify the extent to which our genes affect our lives. If identical twins are more similar to each other with respect to an ailment than fraternal twins are, then vulnerability to the disease must be rooted at least in part in heredity.

These two lines of research — studying the differences between identical twins to pinpoint the influence of environment, and comparing identical twins with fraternal ones to measure the role of inheritance — have been crucial to understanding the interplay of nature and nurture in determining our personalities, behavior, and vulnerability to disease.

The idea of using twins to measure the influence of heredity dates back to 1875, when the English scientist Francis Galton first suggested the approach (and coined the phrase ‘nature and nurture’). But twin studies took a surprising twist in the 1980s, with the arrival of studies into identical twins who had been separated at birth and reunited as adults. Over two decades 137 sets of twins eventually visited Thomas Bouchard’s lab in what became known as the Minnesota Study of Twins Reared Apart. Numerous tests were carried out on the twins, and they were each asked more than 15,000 questions.

Bouchard and his colleagues used this mountain of data to identify how far twins were affected by their genetic makeup. The key to their approach was a statistical concept called heritability. In broad terms, the heritability of a trait measures the extent to which differences among members of a population can be explained by differences in their genetics. And wherever Bouchard and other scientists looked, it seemed, they found the invisible hand of genetic influence helping to shape our lives.

Lately, however, twin studies have helped lead scientists to a radical new conclusion: that nature and nurture are not the only elemental forces at work. According to a recent field called epigenetics, there is a third factor also in play, one that in some cases serves as a bridge between the environment and our genes, and in others operates on its own to shape who we are.

Epigenetic processes are chemical reactions tied to neither nature nor nurture but representing what researchers have called a ‘third component’. These reactions influence how our genetic code is expressed: how each gene is strengthened or weakened, even turned on or off, to build our bones, brains and all the other parts of our bodies.

If you think of our DNA as an immense piano keyboard and our genes as the keys — each key symbolizing a segment of DNA responsible for a particular note, or trait, and all the keys combining to make us who we are — then epigenetic processes determine when and how each key can be struck, changing the tune being played.

One way the study of epigenetics is revolutionizing our understanding of biology is by revealing a mechanism by which the environment directly impacts on genes. Studies of animals, for example, have shown that when a rat experiences stress during pregnancy, it can cause epigenetic changes in a fetus that lead to behavioral problems as the rodent grows up. Other epigenetic processes appear to occur randomly, while others are normal, such as those that guide embryonic cells as they become heart, brain, or liver cells, for example.

Geneticist Danielle Reed has worked with many twins over the years and thought deeply about what twin studies have taught us. ‘It’s very clear when you look at twins that much of what they share is hardwired,’ she says. ‘Many things about them are absolutely the same and unalterable. But it’s also clear, when you get to know them, that other things about them are different. Epigenetics is the origin of a lot of those differences, in my view.’

Reed credits Thomas Bouchard’s work for today’s surge in twin studies. ‘He was the trailblazer,’ she says. ‘We forget that 50 years ago things like heart disease were thought to be caused entirely by lifestyle. Schizophrenia was thought to be due to poor mothering. Twin studies have allowed us to be more reflective about what people are actually born with and what’s caused by experience.’

Having said that, Reed adds, the latest work in epigenetics promises to take our understanding even further. ‘What I like to say is that nature writes some things in pencil and some things in pen,’ she says. Things written in pen you can’t change. That’s DNA. But things written in pencil you can. That’s epigenetics. Now that we’re actually able to look at the DNA and see where the pencil writings are, it’s sort of a whole new world.’

剑桥雅思官方范文(篇九)

The pie chart below shows the main reasons why agricultural land becomes less productive. The table shows how these causes affected three regions of the world during the 1990s.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

剑桥雅思官方范文(篇十)

Task:Some people say that playing computer games is bad for children in every aspect. Others say that playing computer games can have positive effects on the way children develop. Discuss both views and give your opinion.

Sample answer:

In recent years, the prevalence of computer games has exerted a significant effect on children's life. As to whether they affect children negatively, there is an endless debate. Despite the fact that playing computer games is an effective way to relieve pressure, the problems associated with study and health cannot be neglected.

Clearly, playing computer games is regarded as a main factor leading to poor academic performance. With the entertaining nature, computer games will easily distract children from their studious pursuits. With the passage of time, children will probably fall behind their peers in academic development. In addition, when children spend too much time playing computer games, they are less likely to participate in physical activities, which is one reason why many children suffer from obesity. As a result, these overweight children’s confidence may be undermined and their health may be negatively influenced as well.

Despite these disadvantages, the advantages can still not be ignored. First of all, the latest research shows that game-playing helps children to hone their communication and interpersonal skills. In many cases, players work together in teams to achieve goals, competing against other players. Therefore, their social skills and teamwork spirit are put to the test. Also, computer games can have positive and therapeutic effects on players. Games provide an opportunity for children to decompress and tune out of strains and stresses of everyday life. Giving their mind time to rest is critical for emotional and mental well-being.

In conclusion, it is not advisable for children to play computer games, for the reasons that it not only has a negative impact on their study, but also makes them lose confidence, although computer games provide a form of relaxation.

显示全文

注:本文部分文字与图片资源来自于网络,转载此文是出于传递更多信息之目的,若有来源标注错误或侵犯了您的合法权益,请立即后台留言通知我们,情况属实,我们会第一时间予以删除,并同时向您表示歉意

点击下载文档

文档为doc格式

发表评论

评论列表(7人评论 , 39人围观)

点击下载
本文文档