基于考生回忆投稿及材料收集整理 — 非官方 IELTS 资料。
Reading Passage 1: Spider Silk
A Scientists have succeeded in copying the silk-producing genes of the Golden Orb Weaver spider and are using them to create a synthetic material which they believe is the model for a new generation of advanced bio-materials. The new material, biosilk, which has been spun for the first time by researchers at DuPont, has an enormous range of potential uses in construction and manufacturing.
B The attraction of the silk spun by the spider is a combination of great strength and enormous elasticity, which man-made fibres have been unable to replicate. On an equal-weight basis, spider silk is far stronger than steel and it is estimated that if a single strand could be made about 10m in diameter, it would be strong enough to stop a jumbo jet in flight. A third important factor is that it is extremely light. Army scientists are already looking at the possibilities of using it for lightweight, bulletproof vests and parachutes.
C For some time, biochemists have been trying to synthesise the drag-line silk of the Golden Orb Weaver. The drag-line silk, which forms the radial arms of the web, is stronger than the other parts of the web and some biochemists believe a synthetic version could prove to be as important a material as nylon, which has been around for 50 years, since the discoveries of Wallace Carothers and his team ushered in the age of polymers.
D To recreate the material, scientists, including Randolph Lewis at the University of Wyoming, first examined the silk-producing gland of the spider. 'We took out the glands that produce the silk and looked at the coding for the protein material they make, which is spun into a web. We then went looking for clones with the right DNA,' he says.
E At DuPont, researchers have used both yeast and bacteria as hosts to grow the raw material, which they have spun into fibres. Robert Dorsch, DuPont's director of biochemical development, says the globules of protein, comparable with marbles in an egg, are harvested and processed. 'We break open the bacteria, separate out the globules of protein and use them as the raw starting material. With yeast, the gene system can be designed so that the material excretes the protein outside the yeast for better access,' he says.
F 'The bacteria and the yeast produce the same protein, equivalent to that which the spider uses in the draglines of the web. The spider mixes the protein into a water-based solution and then spins it into a solid fibre in one go. Since we are not as clever as the spider and we are not using such sophisticated organisms, we substituted man-made approaches and dissolved the protein in chemical solvents, which are then spun to push the material through small holes to form the solid fibre.'
G Researchers at DuPont say they envisage many possible uses for a new biosilk material. They say that earthquake-resistant suspension bridges hung from cables of synthetic spider silk fibres may become a reality. Stronger ropes, safer seat belts, shoe soles that do not wear out so quickly and tough new clothing are among the other applications. Biochemists such as Lewis see the potential range of uses of biosilk as almost limitless. 'It is very strong and retains elasticity: there are no man-made materials that can mimic both these properties. It is also a biological material with all the advantages that have over petrochemicals,' he says.
H At DuPont's laboratories, Dorsch is excited by the prospect of new super-strong materials but he warns they are many years away. 'We are at an early stage but theoretical predictions are that we will wind up with a very strong, tough material, with an ability to absorb shock, which is stronger and tougher than the man-made materials that are conventionally available to us,' he says.
I The spider is not the only creature that has aroused the interest of material scientists. They have also become envious of the natural adhesive secreted by the sea mussel. It produces a protein adhesive to attach itself to rocks. It is tedious and expensive to extract the protein from the mussel, so researchers have already produced a synthetic gene for use in surrogate bacteria.
Questions 1–5
The passage has nine paragraphs, A–I.
Which paragraph contains the following information?
Write the correct letter, A–I, in boxes 1–5 on your answer sheet.
- 1
a comparison of the ways two materials are used to replace silk-producing glands
- 2
predictions regarding the availability of the synthetic silk
- 3
ongoing research into other synthetic materials
- 4
the research into the part of the spider that manufactures silk
- 5
the possible application of the silk in civil engineering
Questions 6–10
Complete the flow-chart below.
Write NO MORE THAN TWO WORDS from the text for each answer.
Synthetic gene grown in (6) ________ or (7) ________
↓
globules of (8) ________
↓
dissolved in (9) ________
↓
passed through (10) ________
↓
to produce a solid fibre
Questions 11–13
Do the following statements agree with the information given in the text?
In boxes 11–13 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
- 11
Biosilk has already replaced nylon in parachute manufacture.
- A. TRUE
- B. FALSE
- C. NOT GIVEN
- 12
The spider produces silk of varying strengths.
- 13
Lewis and Dorsch co-operated in the synthetic production of silk.
Reading Passage 2: Introduction To A Book About The Assessment Of Carbon Footprints
A As this book is about ways of measuring the carbon footprint of particular things, I should start by making it clear what I mean. I am using the word ‘carbon’ as shorthand for all the different global-warming greenhouse gases, and I am using the word ‘footprint’ as a metaphor for the total impact that something has. So I am using the phrase ‘carbon footprint’ as shorthand to mean the full climate-change impact of something. That something could be anything – an activity, an item, a lifestyle, a company, a country, or even the whole world.
B Measuring carbon footprints is a long way from being an exact process, whatever the claims, or whatever numbers you might see written on the side of products in some shops. All my numbers are best estimates, and nothing more, even though I have reached them as carefully as I can.
C I have used a variety of different methods and sources. I have drawn on a range of data sets and models taken from publicly available reports of life-cycle studies. I have also used studies carried out for businesses across different industries by my own company, Small World Consulting, using models that we are developing all the time. Often I have arrived at numbers by a couple of different routes, to check that the results agree with each other. Occasionally, it has been more a case of putting my finger in the air and guessing, but when that has been the case I have tried to make it clear.
D The publicly available data sets I have used were arrived at by two main methods. The first of these, process-based life-cycle analysis, is the most common approach to carbon footprint calculations. It is often referred to as ‘bottom-up’ because you start off identifying, one by one, all the processes that have had to happen in order for, say, a product to be created. Then you add up the emissions from each process, and that is the footprint of the product. It may sound simple, but it is not at all. It is back-breaking work, and since the number of processes you really need to include is always infinite, the job is never quite complete, so you end up with an underestimate. In fact, the omissions from the calculation are often shocking: they can be fifty per cent or more. To make matters worse, these problems are commonly overlooked, even in the development of government-backed and government-funded guidelines, such as the UK’s PAS 2050 standard. But for all the problems, process-based life-cycle analysis is still an essential source of detailed information that can’t be gathered any other way.
E The other method is environmental input-output analysis. This is a neat alternative to process-based life-cycle analysis. It is not as popular, perhaps because it is a bit less easy to understand, but it is at least as robust as anything else in the dim world of measuring carbon footprints. It is sometimes called a ‘top-down’ approach because it begins by looking at the whole economy. It uses macroeconomic modelling to understand the way in which the activities of one industry trigger activities and emissions in every other industry. Input-output analysis’ key ‘trick’ is a piece of ingenious maths (for which a man called Wassily Leontief got a Nobel Prize) that succeeds in capturing the endless ripple effects in a way that is one hundred per cent complete. It has the further advantage that if you know how much something costs, you can get an instant crude estimate of its carbon footprint. It is like a magic trick. And just like all the best magic it is also a bit too good to be true – in many cases the results can be ridiculously general and of little value.
F Input-output analysis is nevertheless a natural method, both because it does not omit things, and because once a specific model has been built it is often easy to use: the basic technique is well established. The specific model I have used is one that was developed at Small World Consulting in collaboration with Lancaster University in the UK, and draws mainly on data obtained from government sources. It was based on a 2007 picture of the UK economy. It deals with all the greenhouse gases, and employs a weighting factor for gases emitted at a high altitude, which have a greater impact than ground-level emissions. A key weakness, which I sometimes adjust for, is that it treats imported products as though they had the same carbon intensity as products from within the UK, whereas in reality imports are usually more carbon-intensive.
G Most of the time I have used a combination of life-cycle analysis and input-output analysis to get my numbers. At its best, life-cycle analysis can be more precise, but input-output analysis is often able to get at information that life-cycle analysis is unable to reach. Putting the two methods together is sometimes called a hybrid approach, and the result is a bit like looking through both a microscope and a telescope at the same time. They each show you different things, and between them, if the lenses are clean, you end up with a passable understanding of whatever it is you are looking at.
Questions 14–19
Reading Passage 2 has seven paragraphs, A–G.
Which paragraph contains the following information?
Write the correct letter, A–G, in boxes 14–19 on your answer sheet.
NB You may use any letter more than once.
- 14
reference to an award-winning formula
- 15
an acknowledgement of the general shortcomings of carbon footprint calculations
- 16
mention of a working partnership
- 17
reference to the demanding nature of one way of calculating carbon footprints
- 18
the advantage of combining two different methods
- 19
a comparison between goods from home and abroad
Questions 20–21
Choose TWO letters, A–E.
The list below describes some of the possible features of process-based life-cycle analysis.
Which TWO of these features are mentioned by the writer of the passage?
- 20–21
Which TWO of these features of process-based life-cycle analysis are mentioned by the writer of the passage?
- A. It is more complicated than it sounds.
- B. It usually produces exaggerated results.
- C. It is a frequently used procedure.
- D. Its faults are widely recognised.
- E. It was first developed in the UK.
Questions 22–23
Choose TWO letters, A–E.
The list below describes some of the possible features of environmental input-output analysis.
Which TWO of these features are mentioned by the writer of the passage?
- 22–23
Which TWO of these features of environmental input-output analysis are mentioned by the writer of the passage?
- A. It is often the basis of national guidelines.
- B. Its starting point is the manufacturing process.
- C. It is comprehensive in scope.
- D. It is a relatively new method of calculation.
- E. It can use prices to get approximate carbon footprints.
Questions 24–26
Complete the summary below.
Choose ONE WORD ONLY from the passage for each answer.
Small World Consulting
Small World Consulting has collaborated with a UK university to develop a version of the environmental input-output model of analysis, using data provided by the (24) ________ about the UK economy in 2007. This model is able to take into account the altitude at which greenhouse gases are produced. A significant (25) ________ is that it does not distinguish between (26) ________ of different origin, but the writer occasionally makes allowances for that.
Reading Passage 3: Risk Taking
A We run risks. Most of the time we ignore them; sometimes we stop and decide how to deal with them. That’s life. Risks arise in sports, in business, in personal relationships; they are present in the laboratory, in political calculations, everywhere. Acting individually, we often prefer to gain some benefit by accepting some danger. Acting collectively, we make similar trade-offs.
B When society must assess risks, and those risks can be clarified, at least in part, by science, technology or mathematics, the responsibility of the research community is to be clear and complete. But that is not always so easy. Furthermore, too few people pay full attention to the best evidence, much less modify their behaviors as a result. Even when the evidence of high risk is clear – about smoking, for instance – many will deny the risk, or dispute it, or accept that it exists and still go ahead. As a former cigarette smoker, I understand denial.
C Perhaps more important than the basic facts of risk are the varied perception of it. Hearing the prediction of 60% chance of rain, or recognizing the minuscule likelihood of becoming ill from a flu shot, most people understand the right responses: take your umbrella and get your flu shot. But some, fearfully but irrationally, go to the extreme and stay at home and avoid all contact with other people. Irrational decisions occasionally affect us all. When it comes to risks the best odds do not always influence people to make the correct decision.
D In her book, The Universe and the Teacup, the science writer K. C. Cole reminds us that the risks of losing something and gaining something appear to be calculated in our minds according to quite different scales. People will risk a lot to prevent a loss, she notes; some people will rush into a burning building to save a pet. But they will usually risk very little if the only perceived outcome is a possible gain; many people won’t even risk pursuing an exciting job, if the current job, though unfulfilling, remains comfortable. That psychological mechanism, a desire to maintain the status quo, helps explain the high hurdles that any rational risk assessment must confront.
E Organizations face the same hurdles whenever they must cope with major shifts in policy. In his classic examination of the character of high-tech industry, Only the Paranoid Survive, Andrew S. Grove gives a perceptive account of a crisis that took place during his tenure as Chairman of the Intel Corporation. The business environment for Intel and its competitors was transformed by a flood of low-cost memory chips from Japan, and Intel made the difficult decision to abandon its chip-making business. Such a period of change in the outside world is filled with danger, Grove notes, precisely because it is so easy for executives to try to disregard it or misinterpret the mounting evidence showing the profound risks of not making change at the very core. The distinction Cole cites is instructive here: one reason management and staff may not act is that they tend to focus on the potential gains of risking change (which they characterize as small), rather than on the catastrophic losses that risking change could prevent. The period becomes critical for a company, according to Grove, and deadly when unattended to.
F Likewise, at the national level, and even the global one, institutions tend to be more willing to take a risk if it means avoiding a loss, than they are if it might confer a gain. Almost everyone, for instance, sees the signs of ecological decay. Reid J. Lifset’s article, ‘Full Accounting’, describes newly developed techniques for clarifying which critical decision would have the highest pay-offs for the environment. Once these ‘leverage points’ as he calls them, are located, many environmental organizations will be willing to risk the resources needed to prevent further deterioration.
G More complicated are decisions by nations to invest broadly in educational research. Some governmental leaders are oblivious to the risks posed by social underinvestment, because the urgent needs of the present take precedence over actions that would give rise to even more substantial gains in the future. Their attitude is that today’s risks must be manageable, and that tomorrow’s gains are at the very least difficult to measure. Better consideration and decision making for what lies ahead is essential.
H Nevertheless, I confess to being an optimist. My glass is generally half full – though that may not help me handle risk. Whether one’s temperament is optimistic or pessimistic, everyone in our scientific and engineering community has a social responsibility: measure with care and portray with honesty the level of risk involved in any action or decision.
Questions 27–30
Complete each sentence with the correct ending, A–G, below.
Write the correct letter, A–G, in boxes 27–30 on your answer sheet.
A planning for the future.
B predicting their errors.
C continuing in the present situation.
D recent findings on the most effective solutions to problems.
E achieving a gain.
F changes occurring externally.
G a high level of agreement.
- 27
K. C. Cole points out that avoiding a loss seems more important to people than ________
- 28
According to Andrew S. Grove, it can be very dangerous for companies to ignore ________
- 29
Reid J. Lifset argues that environmental agencies can benefit from ________
- 30
The writer suggests that government leaders need to focus more on ________
Questions 31–39
Reading Passage 3 has eight paragraphs, A–H.
Which paragraph contains the following information?
Write the correct letter, A–H, in boxes 31–39 on your answer sheet.
NB You may use any letter more than once.
- 31
the areas of study that help us understand risk
- 32
reference to key actions that might benefit the world
- 33
examples of statistical predictions that the majority of the public react to in the same way
- 34
the variety of contexts in which risk occurs
- 35
mention of a habit that has been proved to be very risky
- 36
reference to market forces motivating change
- 37
the writer's current attitude towards risk
- 38
a reason why some individuals avoid making a career change
- 39
how some people over-react to information about risk
Question 40
Choose the correct letter, A, B, C or D.
Write the correct letter in box 40 on your answer sheet.
- 40
At the end of the passage the writer concludes that
- A. risk is something we must try to avoid.
- B. experts should be truthful about risk to the public.
- C. optimists are better able to deal with risk than pessimists.
- D. it is important to take risks in order to fulfil social obligations.
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