اصطلاح موردنظر خود را اینجا بیابید...
The power of light
Light the world to us. It sets our biological clocks. It in our brains the sensations of colour. Light feeds us, supplying the energy for plants to grow. It us with special effects like rainbows and sunsets. Light gives us life-changing tools, from (show me the picture) to lasers and .
There has been light from the beginning. There will be light, , at the end. In all its forms, visible and invisible, it the universe. Light is more than a little bit . Modern physics has sliced the stuff of nature into ever smaller and more , but light won’t reduce. Light is light- , but not simple. No one is quite sure how to describe it. A wave? A ? Yes, the scientists say Both.
in our daily lives that we hardly pay any attention to it. Light is almost like air. It’s a given. A human would no more the concept of light than a fish would the of water. There are , certain moments of when a particular of light, a ; appears: a rainbow, a sunset, a flash of lightning in a dark sky the surface of the sea at , the in a forest, the little red dot from a professor’s laser pointer. The of a candle, a room with romance. The searching for the after a .
EX: The flowers and tears at the funeral were a measure of people's love for her.
گل ها و اشک های ریخته شده در مراسم تدفین نشان عشق مردم به او بود.
Usually, though, we don’t see light, we see with it. You can’t appreciate the beauty of a rose if you ponder that the colour red is just the brain’s of a specific of Light with that are roughly 700 nanometres apart. A told me that she’s doing her job best when no one notices the lights at all. Her goal is to create an atmosphere, a mood - not to show off the fancy new filters that create colours of .
Light is now used for everything from laser eye to telephone technology. It could even become the main power source for long- distance space travel. The would have an sail to catch the ‘wind’ of light from an Earth-based laser. In theory such a could to a of the speed of light, without carrying fuel.
What we call light is really the same thing in a different set of wavelengths as the radiation that we call radio waves or gamma rays or x- rays. But visible light is unlike any other fundamental element of the universe: it directly, regularly and dramatically our senses. Light offers information across great distances. You can’t hear or smell the moons of Jupiter or the Crab Nebula. So much of importance is communicated by visible light that almost everything from a to an octopus has a way to capture it - an eye, eyes, or something similar.
our eyes are designed to detect the kind of light that is radiated by the particular star that gives life to our planet: the sun. Visible light is powerful stuff, moving at relatively short wavelengths, which makes it biologically . To see long, radio waves, we’d have to have huge eyes like satellite dishes. ! Nor would it make sense for our eyes to light (though some deep-sea shrimp near do see this way). We’d be , because in these wavelengths any object . That would include almost everything around us.
There is also darkness in the daytime: shadows. There are many kinds of shadows, more than I realized until I consulted and shadow expert David Lynch in Topanga Canyon, up the coast from Santa Monica, California. Lynch points out that a shadow is filled with light reflected from the sky, it would be completely black. Black is the way shadows on the moon looked to the Apollo , because the moon has no atmosphere and thus no sky to light into the of the .
Lynch is a man who, when he looks at a rainbow, details that most of us. He knows, for example, that all rainbows come in pairs, and he always looks for the second rainbow: a , rainbow, with the colours . The region is darker. That area has a name, wouldn’t you know: Alexander’s dark band. As I the spectacular view across the canyon, Lynch explained something else: ‘the reason those mountains over there look a little blue,’ he said, the range that the Pacific, ‘is because there’s sky between here and those mountains. It’s called airlight.’
What next for light? What new application will we see? What information will deliver to our telescopes? Will the rotating disco ball (show me the picture) ever ? Above all, you have to wonder: will we ever fully understand light?
There have been recent about scientists finding ways to make light go faster than the speed of light. This is what science fiction writers and certain have dreamed of for decades. If you could make a spaceship that wasn’t by Einstein’s speed limit, they , you could the universe far more easily.
Lijun Wang, a research scientist at Princeton, managed to create a of light that went faster than the supposed speed limit. ‘We created an of gas in which the speed of a pulse of light the speed of light in a ,’ he said, ‘but this is not Einstein. ’ Even though light can be to go faster than light, matter can’t. Information can’t. There’s no possibility of time travel.
I asked Wang why light goes 186,282 miles a second and not some other speed. ‘That’s just the way nature is,’ he said. There are scientists who don’t like ‘why’ questions like this. The speed of light is just what it is. That’s their belief. Whether light would move at a different in a different universe is something that is currently outside the scope of experimental science. It’s even a bit ‘out there’ for the theorists.
What’s certain is that light is going to remain extremely useful for industry, science, art, and our daily, . Light our reality at every scale of existence. It’s an amazing tool, a carrier of beauty; . that it has a very bright future.
The reading passage describes a number of cause and effect relationships. Match each Cause (1-5)
in List A, with its Effect (A-H) in List B. There are more Effects in List B than you will need, so you
will not use all.
List A Causes
|1. Much of the time, visible light is all around us.
2. Light can sometimes appear in an interesting way.
3. Visible light carries a lot of essential information.
4. Without an atmosphere, light is not reflected onto solid surfaces.
5. Only light can exceed 186,282 miles per second.
List B Effects
|A. Nearly all living creatures can detect it.
B. There is a dark gap between rainbows.
C. Light from Earth could power a spacecraft.
D. Shadows are totally black.
E. We cannot return to the past.
F. We don’t really notice or think about it.
G. Certain creatures can detect infra—red light.
H. We instantly become aware of it.
Do the following statements agree with the views of the writer in Reading Passage 1? Write
YES the statement agrees with the views of the writer
NO the statement does not agree with the views of the writer
NOT GIVEN there is no information about this in the passage
6. It is difficult to find a single word to say exactly what light is.
7. Thinking about the physics of light can make an object seem even more beautiful.
8. Light from the sun makes it possible for life to exist on other planets.
9. It is more practical for humans to detect visible light rather than radio waves.
10. David Lynch sometimes notices things that other people don’t.
Answer the following questions using NO MORE THAN THREE WORDS for each answer.
11. What appearance can the land have when seen from a distance?..........................
12. In what have some people imagined travelling? ..................................
13. In what substance did light go faster than previously thought possible?...............................
To MBA or not to MBA
‘You could be forgiven for thinking just about has an MBA these days,’ says Anthony Hesketh, of Lancaster University management school. We know what he means. Such is the worldwide growth and awareness of the MBA that this icon of career advancement and high salaries has almost become education in the business sector.
NOTE : Such is ......
Ex: Such is world that .....
دنیا اینطوری شده که
Such is the worldwide growth and awareness of the MBA that
رشد و آگاهی جهانی از ام بی ای اینطوری شده که ....
In reality, many postgraduate to an MBA exist. The total number of MBA programmes worldwide is around 2,400, while other masters and advanced courses in the whole of business education add up to more than l0,000.
Two key exist in matching what students want with what the universities offer: first is versus , and second is pre-experience versus post-experience and the two distinctions are . Carol Blackman, of the University of Westminster school of business, explains the first distinction. ‘Specialist masters programmes are designed either for career preparation in a clearly defined type of job or profession, or are intended to develop or professional in individuals . The aim is to increase the depth of their knowledge in the specialist area. The MBA, on the other hand, is a general management programme which provides with an opportunity for personal development with a introduction to all management subject areas and the and of management’.
Specialist knowledge, however, is not everything finding a job. Surveys by the UK’s of Graduate Recruiters (AGR) repeatedly confirm that what employers , and continue to find , are the personal skills that will make graduates valuable employees. In fact, when recruiting new graduates most employers considered these skills more important than specialist knowledge. What employers seek most from new graduates are and, interpersonal skills, team working and good communication. Of the nineteen skills considered important in AGR’s 2002 survey, just three require specialist education - , computer and foreign languages – and these are low on the list.
Nunzio Quacquarelli, of topcareers.net, . ‘Clearly, for those with a second degree, but no significant work experience, do not match those of a good MBA and a number of years in the workplace. According to the AGR research, about l4% of employers offered a better salary to those new graduates with a masters - or even a doctorate. In my view, the salary improvement of l0% to I5% largely the recruit’s age and rather than the increase in perceived by the employer. Contrast this with our latest topmba.com MBA Recruiters Survey results which shows that the average salary paid to an MBA with good work experience in the US and Europe is US$80,000 — around two and a half times the average for a young postgraduate.’
Anthony Hesketh poses the question whether holding a second degree may even be a disadvantage. ‘l have seen many reports over the years suggesting that employers view postgraduates as less employable than those with a first degree. Drive, motivation and career focus, not to mention ability, are what employers value and are prepared to pay for. A postgraduate immediately has an task explaining an additional year; or three years, of study.’
This view may seem , but, if you are about to graduate and are considering a further degree, you should take the realities into account and ask yourself some hard questions:
- Is the qualification l am considering going to impress employers?
- Is it going to over less qualified candidates?
- Is my consideration of a second degree because l am not sure of my career direction?
- Will employers consider that I lack drive and because I have my attempts to find a job?
Many postgraduate options exist that can help you to the personal skills that employers in the world of business are seeking. Consider, for example, the offerings of Strathclyde and Durham universities.
According to Dr Nic Beech, of the University of Strathclyde graduate school of business: ‘The MSc in business management (MBM), offered at USGSB is suitable for students with a good first degree - particularly a non-business first degree — but little or no business experience. Our MBM offers these graduates the opportunity to combine the specialization of their first degree with a general management qualification – something employers recognize produces a individual.
Graduates tell us that the MBM allows them to access sectors . It is designed to develop the business knowledge, practical experience and personal skills which employers are seeking.’
At the University of Durham business school, Sheena Maberly is careers development officer; she too sees high value in qualifications such as the Durham MA in management (DMAM). She says: ‘Whatever your first degree, from to , a postgraduate business degree can help you in an job market. If you’re just starting out in your career, a business master’s degree like the DMAM will enable you to develop skills directly relevant to employers’ needs. So, extending your studies into management can make you better to ‘’ — and that’s what employers expect. Recruiters are highly and a qualification is additional evidence of motivation.
Before yourself to postgraduate study, the options. Perhaps the best route might be to take a job now and plan to do an MBA a few years ? Try to get sponsorship from a company. Or go for a well researched and masters that will help you. Ultimately the choice is yours, but focus on the future, and on your target employer’s .
Do the following statements agree with the information given in Reading Passage 2? Write
TRUE the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN there is no information on this
14. British employers are more interested in what potential recruits can do than what they know.
15. A recruit with a specialist masters usually earns as much as an experienced employee with a
16. The writer claims that undergraduates often plan to do a masters because they can’t decide what career to follow.
Question 14 :
The text quotes various individuals. Match the four people A-D with the four points made in
Questions 17-21. You may use any of the people more than once.
17.Employees with postgraduate qualifications earn more because they are older and expect more.
18.It can be difficult to convince an employer that the extra time spent at university was necessary.
19.One type of course focuses on a particular aspect of business, whereas the other is more general in approach.
20.Graduates who have neither worked in nor studied business are suited to our programme.
21. There is evidence that companies may prefer to employ people without a masters degree.
|List of People|
|A Anthony Hesketh
B Carol Blackman
C Nunzio Quacquarelli
D Nic Beech
Question 17 :
Complete the summary below Choose ONE word from Reading Passage 2 for each answer.
According to Sheena Maberly, a second degree can improve the 22..................... prospects of
graduates in any subject. Taking a management MA gives them the 23 ..................... companies are
looking for, and lets them get straight on with the job as soon as they start work. It also shows
they have the 24 ..................... that companies seek. First, however, it is important to consider the
25 ............... : whether to start right away on a carefully chosen postgraduate course, or to do so
after a few years’ work, preferably with financial assistance from the 26.................. . Whichever
they decide, they should think about the 27................... , and what the company wants.
Reading passage 3 has seven paragraphs
A—G. Choose the most suitable headings for paragraphs B—G from the list of headings below.
|List of headings|
i. Looking at a particular decade
Paragraph A Answer v
28. Paragraph B
29. Paragraph C
30. Paragraph D
31. Paragraph E
32. Paragraph F
33. Paragraph G
The Ring Cycle
In the jungle of scientific debate, you cannot always see the wood for the trees. But in climate
change, the wood itself sometimes holds the key Imagine an annual register of a year’s sunshine
and rainfall and frost, kept up to date with perfect accuracy almost everywhere south of the tundra and north of the tropics, and available for inspection not just at any time in life but, quite often, for centuries after death. The register is, of course, the annual growth rings of trees. Match the rings from young trees with those from old forest giants and you have a centuries-long measure of the march of the seasons. Match the rings from old trees with old cathedral rafters and you have a still longer chronology — and a science called dendrochronology.
Dendrochronologists, scientists who study the growth of rings in trees, have successfully
constructed long tree-ring records by overlapping the patterns of wide and narrow rings in
successively older timber specimens. There are now a dozen or so chronologies in the world that
date back more than 5,000 years. These records, normally constructed in a restricted area, using a
single species of tree, are year-by- year records of how the trees reacted to their growth
conditions — an environmental history from the trees’ point of view.
Because tree-ring chronologies are constructed on a regional basis, there has, in the past, been a
tendency for dendrochronologists to think local. However, the success of dendrochronology as
an international research topic means that there are now quite a lot of chronologies available for
study As the chronologies are dated absolutely it is possible to compare the records from
different areas year by year. Recently; an analysis of 383 modern chronologies, drawn from a vast
area across Europe, northern Eurasia and North America was published. The authors, Keith Briffa
and colleagues, observed that the maximum late-wood density of the growth rings in each year
was related to the temperature in the growing season. Their analysis spanned 600 years, back to
AD 1400, and presented a summer temperature record reconstructed from the huge grid of
precisely dated ring densities. What they noticed was that the years of really low density — the
cool summers were directly associated with large explosive eruptions, as known from historical
sources and from dated layers of acid in the Greenland ice record. Greenland ice is kilometres
thick and is made up of the compressed snowfall of tens of thousands of years, so the ice record
can be read in almost the same way as tree-rings. I shall use this study as an example of what else tree-rings can tell us.
The study provides a year-by-year estimate of temperatures, together with the dates of some
major volcanoes. It is a nice clean story — volcanoes load the atmosphere with dust and aerosol
and reflect back sunlight, cooling the earth’s surface. This cooling leads to variations in the
density of growth rings in northern conifers. Because there are a lot of other records, it is
possible to test the findings from the conifer density record.
We can, for example, look at what European oak was doing across the same 600-year period. Was
oak responding in the same way as the conifers? The ‘oak chronology’ is the mean of eight
regional oak chronologies across a strip of land from Ireland to Poland. lt represents how, on
average, hundreds of millions of oaks grew. What we see from this comparison is that the oaks
clearly do respond to the volcanoes in some cases (in 1602, 1740 and 1816, for instance), but
nothing like so clearly in others. Immediately it becomes apparent that the conifers tell only part
of the story. There are many downturns in oak growth, and only a few are related to the conifer record. The oaks were quite capable of being more stressed in years where the conifers were not
affected. The point of this, however, is not to argue about the quality of global cooling; the point is to show what dendrochronology can do.
Take the case of 1816, called the ‘year without a summer’ because of the terrible unseasonable
cold and the crop failures that ensued. It has long been known that the primary cause of the
cooling was the massive eruption of Tambora, east of Java, in 1815. However, there was a lot
more going on in the run—up to 1816. Bald cypress trees in Tennessee show a major growth
anomaly, with rings up to 400 per cent wider than normal, in the years following a huge
earthquake in 1811-12 in Eastern America. But there is a volcanic acid layer in several Greenland
and Antarctic ice cores in 1809-10, as well as in 1815-16. So here we have a combination of a
highly unusual quake in an area of the USA not normally affected by earthquakes, and at least two volcanic eruptions, including Tambora, which is widely regarded as the largest in the last 10,000 years. According to Briffa, the period 1810-20 was the coldest in the last millennium, so we begin to see a combination of three unusual elements in less than ten years — exceptional earthquake, exceptional volcanic eruption, and exceptional cold. Given that the defeat of Napoleon’s invasion of Russia in 1812 was famously attributed to ‘General Winter’, one wonders whether a natural series of events actually helped to change the course of modern history.
Obviously, the case of 1816 and the years just before and after it is relatively recent and well
documented. However, dendrochronology allows us to investigate the effects of such events
geographically, indeed globally. We can interrogate the trees in areas where there is no historical
or instrumental record. Further back in time, dendrochronology is almost the only way to
reconstruct abrupt environmental events and perhaps throw new light on far darker moments in
human history Were there just political forces at work in the Dark Ages, or did violent natural
events also take a hand, tipping the balance by darkening the skies and lowering the
temperature? The trees were there too, and kept a record. The wood hewn from them and
preserved through the centuries is slowly beginning to yield at least circumstantial evidence that
could support some of the stories — think of the Arthurian wasteland, or the plagues of Egypt —
so far told only in enigmatic artefacts, or in legends, epics, and religious chronicles.
Question 28 :
Question 29 :
Question 30 :
Question 31 :
Question 32 :
Question 33 :