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MODEL TEST - ACADEMIC IELTS
(Time: 90 minutes)

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Section 1

Script:

Listen to the telephone conversation between a student and the owner of a paragliding school and answer the questions below.

Man: Hello 'Paragliders' Paradise'. How can I help you?

Maria: Oh hi. I'm interested in doing a course in paragliding.

Man: Which course are you interested in?

Maria: Well, I'm not sure. What's available?

Man: Well ... we've got the introductory course which lasts for two days.

Maria: OK.

Man: Or there's the 4-dav beginners' course which is what most people do first. I'd tend to recommend that one. And there's also the elementary pilot course which takes five to six days depending on conditions.

Maria: We might try the beginner's course. What sort of prices are we looking at?

Man: The introductory is $190; the beginner's course, which is what you'd probably be looking at, is $320 - no, sorry 330 - it's just gone up - and the pilot course is $430. Maria: Right.

Man: And you also have to become a member of our club so that you're insured. That'll cost you $12 a day. Everyone has to take out insurance, you see.

Maria: Does that cover me if I break a leg?

Man: No, I'm afraid not - it's only 3rd party and covers you against damage to other people or their belongings, but not theft or injury, You would need to take out your own personal accident insurance.

Maria: I see! And what's the best way to get to your place? By public transport or could we come by bike? We're pretty keen cyclists.

Man: It's difficult by public transport although there is a bus from Newcastle; most people get here by car, though, 'cos we're a little off the beaten track. But you could ride here OK. I'll send you a map. Just let me take down a few details. What's your name?

Maria: Maria Gentle.

Man: And your address, Maria?

Maria: Well, I'm a student staying with a family in Newcastle.

Man: So it's care of ...

Maria: Care of Mr and Mrs. McDonald.

Man: Like the hamburgers!

Maria: Yes, exactly.

Man: McDonald ...

Maria: The post office box address is probably best. It's PO Box 676. Newcastle.

Man: Is there a fax number there, because I could fax you the information?

Maria: Yes, actually, there is. It's 0249 that's for Newcastle and then double seven five four three one.

Man: OK. Now if you decide to do one of our courses, you'll need to book in advance and to pay when you book. How would you be paying?

Maria: By credit card, if that's OK. Do you take Visa?

Man: Yes, fine. We take all major cards, including Visa.

Maria: OK then. Thanks very much.

Complete the form below. Write NO MORE THAN THREE WORDS for each answer.

TELEPHONE MEMO

Name: Maria Gentle

Address: C/o Mr & Mr (1)…………

(2)………… Newcastle

Fax no: 0249 (3)…………

Type of Card : (4)…………

McDonald/Macdonald/MacDonald 775431 Post Office Box/PO Box 676 credit card/Visa

(1)
(2)
(3)
(4)

Section 2

Script:

You will hear a speak to the group before volunteer preparing the town’s anniversary celebrations.

And now for the preparation plans for the town's 250th anniversary celebrations. We are going to follow the same system we had last year, but with a few changes to increase the party spirit.

First of all, this time we are going to make the concert on the beach open to everyone without charge. This is because we have been given money by the council for the celebration and also because last year we had so many problems with keeping people out who had not paid. And on top of this, people will not have to pay for refreshments either, as these are being donated.

Right now, mmm, we are going to divide into four teams: the first one, the Beach Team, will be responsible for cleaning up the beach on the Saturday morning, picking up litter, bottles, plastic bags, wood and anything else that's lying around. Everyone is meeting at the Beach Shop at 8 am. It's an early start, but we want to give everywhere a good thorough clean. We have had permission from the council to close the beach to get it ready for the anniversary celebration on Sunday.

The second team will be responsible for setting out seating in the square for the speeches and prize giving. Again an early start is preferable, but the vans with the seats can't be there until 9 am, so shall we say that everyone should meet at the Village Hall at 9.30? Starting then will allow extra time if the vans are late.

Complete the table below. Write NO MORE THAN ONE WORD AND/OR A NUMBER for each answer.

Teams	Purpose	Meeting point	Time
Beach Team	pick up litter	Beach (1)………	8 am
Town Team	arrange (2)………	Village Hall	(3)……… am

seating shop 9.30

(1)
(2)
(3)

Section 3

Script:

You will hear two students Sharon and Xiao Li talking to their tutor about the presentation they gave the previous week.

Tutor: So. Sharon and Xiao Li, in your presentation last week you were talking about the digital divide - the gap between those who can effectively use communication tools such as the Internet, and those who can't. And you compared the situation here in Northern Ireland with South-East China. Right, so I asked you to do some sell evaluation, watching the video of your presentation and thinking about the three main criteria you're assessed by - content, structure and technique. What do you think was the strongest feature of the presentation, when you watched it? Sharon?

Sharon: Well. I was surprised actually, because I felt quite nervous but, when I watched the video, it didn't show as much as I expected.

Tutor: So which of the criteria would that come under?

Sharon: Er, confidence?

Tutor: That’s not actually one of the criteria as such Xiao Li?

Xiao Li: Technique? It's body language and eye contact, isn't it. Well, I didn't think I looked all that confident, but I think, that our technique was generally good like the way we designed and used the Powerpoint slides.

Tutor: Mmm. So you both feel happiest about that side of the presentation? OK, now on the negative side, what would you change if you could do it again?

Xiao Li: Well, at first I'd thought that the introduction was going to be the problem but actually I think that was OK. We defined our terms and identified key issues It was more towards the end... the conclusion wasn't too bad but the problem was the questions, we hadn’t really expected there'd be any so we hadn't thought about them that much.

Tutor: Uhuh OK. Anything else?

Sharon: Well, like Xiao Li says, I thought the conclusion was OK, but when I watched us on the video I thought the section on solutions seemed rather weak.

Tutor: Mmm. Can you think why?

Sharon: Well, we explained what people are doing about the digital divide in China and Northern Ireland but I suppose we didn't really evaluate any of the projects or ideas, it was just a list. And that was what people were asking us about at the end, mostly.

Answer the questions below. Write NO MORE THAN THREE WORDS for each answer.

the solutions/their solutions the technique/their technique questions/the questions/students' questions/answering the questions/answering students' questions

What do Sharon and Xiao Li agree was the strongest aspect of their presentation?

Which part of their presentation was Xiao Li least happy with?

Which section does Sharon feel they should have discussed in more depth?

Script:

Tutor: OK. Now, I also asked you to get some peer evaluation, from the other students.

Sharon: Yes, er, well, people said it was interesting, like the fact that in China the Internet was used more for shopping than in Northern Ireland. They said sometimes it was a bit hard to understand because we were talking quite fast... but we didn't think so when we watched the video.

Tutor: No, it’s a bit different though, because you know all this information already. Mmm. If you're hearing it for the first time, you need more time to process it ... that's why signposting the structure and organisation of the talk is important.

Xiao Li: That seemed OK, no one mentioned that as a problem. Some people said that we could have had more on the slides… like some of the other groups had nearly everything they said written up on the visuals as well, but other people said the slides were good, they had just the key point...

Tutor: Yes.

Sharon: And most people said we had quite good eye contact and body language. They all pointed out we'd over run... they all said we were five minutes over but we timed it afterwards on the video and it was only three minutes.

Xiao Li: We were a bit unsure about the background reading at first, but I think we did as much as we could in the time... anyway, no one commented on that under content, but one thing that did come out was that they liked the fact we'd done research on both Northern Ireland and China most other people had just based their research on one country. We managed to get quite a lot of data from the Internet, although we had to do our own analysis and we did our own surveys as well in both countries. So the class gave us best feedback for content but it was all OK.

Tutor: Right. Well, that's quite similar to the feedback I'm giving you I was very impressed by the amount of work you'd done and by your research methodology... so, actually, I’m giving you full marks for content, five. The structure of the presentation was good, but not quite as good as the content, so. I gave that four, and the same for technique. So, well done.

Xiao Li/Sharon: Thank you.

Tutor: Now, the next stage is to write up your report. So, just a few pointers for you here. First of all, in your presentation think your ending was rather abrupt - you suddenly just stopped talking. It wasn't a big problem but think about your dosing sentences in your report - you want to round it off well. One thing I forgot to mention earlier was that I felt a very strong point was that after you'd given your results, you explained then limitations.

Xiao Li: The fact that we didn't have a very reliable sample in terms of age in China?

Tutor: Yes, that section. So don't forget to include that. And you had some excellent charts and diagrams, but maybe you could flesh out the literature review a bit. I can give you some ideas for that later on if you want. OK, is there anything else you want to ask?

Xiao Li/Sharon: No... Thank you. / Thanks.

Complete the sentences below. Write ONE WORD ONLY for each answer.

end/ending literature limitations

The tutor says that the of the presentation seemed rather sudden.

The tutor praises the students′ discussion of the of their results.

The tutor suggests that they could extend the review in their report.

Section 4

Script:

PAULA: Today I’d like to introduce Ted Hunter, who used to rear sheep and poultry but who is here to tell us about a rather unusual type of livestock that he’s been concentrating on in the last few years. Ted Hunter is a member of the Domesticated Ostrich Farming Association, and is here to tell us about the possibilities of breeding and rearing these birds here in this country.

TED: Thank you, Paula. When you look at international restaurant menus and supermarkets they all tend to feature the same range of meats - beef, lamb, chicken, pork, that sort of thing. But people are always interested in something different and we’re now finding that farming can bring new types of meat to our tables. The kangaroo is one animal that’s now being farmed for its meat and eaten outside Australia, where it comes from. It looks and tastes rather like rabbit, though it’s slightly darker in colour, but it is rather tough, so that’s a problem for some people. Crocodiles are also being farmed for their meat. This is rather like chicken, pale and tender, and it’s getting quite fashionable. Some people also find it’s rather fatty, but I think it makes a really tasty sandwich. Now a third type of meat becoming increasingly available, and the one that I think is by far the nicest of the three, is ostrich, which most people say has a similar taste and texture to beef. However, it’s much better for you than beef, as we’ll see later.

Complete the table below. Write NO MORE THAN TWO WORDS for each answer.

"NEW" MEAT	CAN BE COMPARED TO	PROBLEM
kangaroo	(1).........	(2).........
crocodile	chicken	fatty
ostrich	(3).........

tough / rather tough beef rabbit / rabbit meat

(1)
(2)
(3)

Script:

TED: Most people think of ostriches as wild animals, but in fact ostriches have been farmed in South Africa since around 1860. At first they were produced for their feathers. In Africa they were used for tribal ceremonial dress and they were also exported to Europe and America where they were made into ladies’ fans and used for decorating hats. Later, feather fans and big. decorated hats went out of fashion but ostriches were still bred, this time for their hide. This can be treated to produce about half a square metre of leather - very delicate, fine stuff of very good quality. At the same time, some of the meat was used for biltong - the air-dried strips of meat popular in South Africa as a sort of fast food.

Complete the table below. Write NO MORE THAN THREE WORDS for each answer.

OSTRICH PRODUCT	USE
Ostrich feathers	- tribal ceremonial dress - (1)......... - decorated hats
Ostrich hide	(2)...........
Ostrich (3).......	‘biltong’

leather / delicate leather / fine leather / good quality leather fans / ladies' fans / feather fans / ladies' feather fans meat

(1)
(2)
(3)

Passage 1

Ocean Acidification

Caspar Henderson reports on some new concerns.

A few years ago, biologist, Victoria Fabry, saw the future of the world’s oceans in ajar. She was aboard a research ship in the North Pacific, carrying out experiments on a species of pteropod - small molluscs with shells up to a centimetre long, which swim in a way that resembles butterfly flight, propelled by small flaps. Something strange was happening in Fabry’s jars. ‘The pteropods were still swimming, but their shells were visibly dissolving,’ says Fabry. She realised that the animals’ respiration had increased the carbon dioxide (CO2) in the jars, which had been sealed for 48 hours, changing the water’s chemistry to a point where the calcium carbonate in the pteropods’ shells had started to dissolve. What Fabry had stumbled on was a hint of ‘the other CO2 problem’.

It has taken several decades for climate change to be recognised as a serious threat. But another result of our fossil-fuel habit - ocean acidification - has only begun to be researched in the last few years. Its impact could be momentous, says Joanie Kleypas of the National Centre for Atmospheric Research in Boulder, Colorado.

CO2 forms carbonic acid when it dissolves in water, and the oceans are soaking up more and more of it. Recent studies show that the seas have absorbed about a third of all the fossil-fuel carbon released into the atmosphere since the beginning of the industrial revolution in the mid-eighteenth century, and they will soak up much more over the next century. Yet until quite recently many people dismissed the idea that humanity could alter the acidity of the oceans, which cover 71% of the planet’s surface to an average depth of about four kilometres. The ocean’s natural buffering capacity was assumed to be capable of preventing any changes in acidity even with a massive increase in CO2 levels.

And it is - but only if the increase happens slowly, over hundreds of thousands of years. Over this timescale, the release of carbonates from rocks on land and from ocean sediments can neutralise the dissolved CO2, just like dropping chalk in an acid. Levels of CO2 are now rising so fast that they are overwhelming the oceans’ buffering capacity.

In 2003 Ken Caldeira of the Carnegie Institution in Stanford, and Michael Wickett at the Lawrence Livermore National Laboratory, calculated that the absorption of fossil CO2 could make the oceans more acidic over the next few centuries than they have been for 300 million years, with the possible exception of rare catastrophic events. The potential seriousness of the effect was underlined in 2005 by the work of James Zachos of the University of California and his colleagues, who studied one of those rare catastrophic events. They showed that the mass extinction of huge numbers of deep-sea creatures around 55 million years ago was caused by ocean acidification after the release of around 4500 gigatonnes of carbon. It took over 100,000 years for the oceans to return to their normal state.

Around the same time as the Zachos paper, the UK’s Royal Society published the first comprehensive report on ocean acidification. It makes grim reading, concluding that ocean acidification is inevitable without drastic cuts in emissions. Marine ecosystems, especially coral reefs, are likely to be affected, with fishing and tourism based around reefs losing billions of dollars each year. Yet the report also stressed that there is huge uncertainty about the effects on marine life.

The sea creatures most likely to be affected are those that make their shells or skeletons from calcium carbonate, including tiny plankton and huge corals. Their shells and skeletons do not dissolve only because the upper layers of the oceans are supersaturated with calcium carbonate. Acidification reduces carbonate ion concentrations, making it harder for organisms to build their shells or skeletons. When the water drops below the saturation point, these structures will start to dissolve. Calcium carbonate comes in two different forms, aragonite and calcite, aragonite being more soluble. So organisms with aragonite structures, such as corals, will be hardest hit.

So far the picture looks relentlessly gloomy, but could there actually be some positive results from adding so much CO2 to the seas? One intriguing finding, says Ulf Riebesell of the Leibniz Institute of Marine Sciences in Kiel, Germany, concerns gases that influence climate. A few experiments suggest that in more acidic conditions, microbes will produce more volatile organic compounds such as dimethyl sulphide, some of which escapes to the atmosphere and causes clouds to develop. More clouds would mean cooler conditions, which could potentially slow global warming.

Calculating the effect of ocean acidification on people and economies is virtually impossible, but it could be enormous. Take the impact on tropical corals, assuming that warming and other pressures such as pollution do not decimate them first. Reefs protect the shorelines of many countries. Acidification could start eating away at reefs just when they are needed more than ever because of rising sea levels.

‘No serious scientist believes the oceans will be devoid of life,’ says Caldeira. ‘Wherever there is light and nutrients something will live. A likely outcome will be a radical simplification of the ecosystem.’ Taking this and other scientists’ views into account, it seems clear that acidification will mean the loss of many species, so our children will not see the amazingly beautiful things that we can. It is important to tell them to go and see the corals now before it is too late.

Answer the questions below. Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.

over 100,000 years / 100,000 years small flaps / flaps about 1/3 / about a third / 1/3 / a third their shells / the shells / shells rocks / rocks on land coral / corals fishing and tourism / tourism and fishing

What does the pteropod use to move itself through the water?

Which part of the pteropods was being damaged by increased acidification?

What proportion of the carbon released over the last 200 years has been taken in by the oceans?

Where do carbonates enter the oceans from?

How long did the oceans need to recover after the destruction of marine life by acidification 55 million years ago?

Which businesses will suffer if reefs are damaged?

What type of creatures make their skeletons out of aragonite?

Complete the flow-chart below. Choose NO MORE THAN TWO WORDS from the passage for each answer.

global warming cooler clouds the atmosphere / atmosphere microbes

(1)
(2)
(3)
(4)
(5)

Choose the correct answer choice.

1. Which of the following best summarises the writer′s view in the passage?

It is clear that acidification will cause huge damage to marine life.

It is likely that increased CO2 will change marine ecosystems considerably.

We will have to wait and see if acidification has serious effects.

The theory that increased CO2 could have positive results is believable.

Explain:

Passage 2

WHALE STRANDINGS

Why do whales leave the ocean and become stuck on beaches?

When the last stranded whale of a group eventually dies, the story does not end there. A team of researchers begins to investigate, collecting skin samples for instance, recording anything that could help them answer the crucial question: why? Theories abound, some more convincing than others. In recent years, navy sonar has been accused of causing certain whales to strand. It is known that noise pollution from offshore industry, shipping and sonar can impair underwater communication, but can it really drive whales onto our beaches?

In 1998, researchers at the Pelagos Cetacean Research Institute, a Greek non-profit scientific group, linked whale strandings with low- frequency sonar tests being carried out by the North Atlantic Treaty Organisation (NATO). They recorded the stranding of 12 Cuvier’s beaked whales over 38.2 kilometres of coastline. NATO later admitted it had been testing new sonar technology in the same area at the time as the strandings had occurred. ‘Mass’ whale strandings involve four or more animals. Typically they all wash ashore together, but in mass atypical strandings (such as the one in Greece), the whales don't strand as a group; they are scattered over a larger area.

For humans, hearing a sudden loud noise might prove frightening, but it does not induce mass fatality. For whales, on the other hand, there is a theory on how sonar can kill. The noise can surprise the animal, causing it to swim too quickly to the surface. The result is decompression sickness, a hazard human divers know all too well. If a diver ascends too quickly from a high-pressure underwater environment to a lower-pressure one, gases dissolved in blood and tissue expand and form bubbles. The bubbles block the flow of blood to vital organs, and can ultimately lead to death.

Plausible as this seems, it is still a theory and based on our more comprehensive knowledge of land-based animals. For this reason, some scientists are wary. Whale expert Karen Evans is one such scientist. Another is Rosemary Gales, a leading expert on whale strandings. She says sonar technology cannot always be blamed for mass strandings. "It’s a case-by-case situation. Whales have been stranding for a very long time - pre-sonar.” And when 80% of all Australian whale strandings occur around Tasmania, Gales and her team must continue in the search for answers.

When animals beach next to each other at the same time, the most common cause has nothing to do with humans at all. "They're highly social creatures,” says Gales. "When they mass strand - it’s complete panic and chaos. If one of the group strands and sounds the alarm, others will try to swim to its aid, and become stuck themselves.”

Activities such as sonar testing can hint at when a stranding may occur, but if conservationists are to reduce the number of strandings, or improve rescue operations, they need information on where strandings are likely to occur as well. With this in mind, Ralph James, physicist at the University of Western Australia in Perth, thinks he may have discovered why whales turn up only on some beaches. In 1986 he went to Augusta, Western Australia, where more than 100 false killer whales had beached. “I found out from chatting to the locals that whales had been stranding there for decades. So I asked myself, what is it about this beach?” From this question that James pondered over 20 years ago, grew the university's Whale Stranding Analysis Project. Data has since revealed that all mass strandings around Australia occur on gently sloping sandy beaches, some with inclines of less than 0.5%. For whale species that depend on an echolocation system to navigate, this kind of beach spells disaster. Usually, as they swim, they make clicking noises, and the resulting sound waves are reflected in an echo and travel back to them. Flowever, these just fade out on shallow beaches, so the whale doesn’t hear an echo and it crashes onto the shore.

But that is not all. Physics, it appears, can help with the when as well as the where. The ocean is full of bubbles. Larger ones rise quickly to the surface and disappear, whilst smaller ones - called microbubbles - can last for days. It is these that absorb whale 'clicks! "Rough weather generates more bubbles than usual,” James adds. So, during and after a storm, echolocating whales are essentially swimming blind.

Last year was a bad one for strandings in Australia. Can we predict if this - or any other year - will be any better? Some scientists believe we can. They have found trends which could be used to forecast ‘bad years’ for strandings in the future. In 2005, a survey by Klaus Vanselow and Klaus Ricklefs of sperm whale strandings in the North Sea even found a correlation between these and the sunspot cycle, and suggested that changes in the Earth’s magnetic field might be involved. But others are sceptical. “Their study was interesting ... but the analyses they used were flawed on a number of levels,” says Evans. In the same year, she co-authored a study on. Australian strandings that uncovered a completely different trend. “We analysed data from 1920 to 2002 ... and observed a clear periodicity in the number of whales stranded each year that coincides with a major climatic cycle.” To put it more simply, she says, in the years when strong westerly and southerly winds bring cool water rich in nutrients closer to the Australia coast, there is an increase in the number of fish. The whales follow.

So what causes mass strandings? “It's probably many different components,” says James. And he is probably right. But the point is we now know what many of those components are.

Choose NO MORE THAN TWO WORDS from the passage for each answer.

around Tasmania/ Tasmania skin/ skin samples sperm/ sperm wales/ sperm whale noise/ noise pollution

What do researchers often take from the bodies of whales?

What do some industries and shipping create that is harmful to whales?

In which geographical region do most whale strandings in Australia happen?

Which kind of whale was the subject of a study in the North Sea?

Label the diagram below. Choose NO MORE THAN TWO WORDS from the passage for each answer.

blood sound waves microbubbles nutrients

(1)
(2)
(3)
(4)

Passage 3

LIFE, BUT NOT AS WE KNOW IT

Henry Gee

Astrobiology is arguably the trendiest buzzword in science after genomics. Like genomics, it is as hip as it is hard to define. Broadly speaking, it is an umbrella term for the efforts of many scientists working in diverse fields to understand the conditions of life in the universe, whether on Earth or elsewhere.

The canvas is, in fact, so broad that many scientists might be astrobiologists without knowing it: astrobiology adds glamour to all science, from astronomy to zoology. Those with long memories and a cynical mien will have seen all this before. Once upon a time, there was a research programme called exobiology. Is astrobiology a new name for repackaged goods?

No, for two reasons. First, many discoveries made in the past decade have set people thinking, once again, about life elsewhere. For example, hardly a month goes by without the discovery of yet another planet orbiting a distant star. And whatever the truth about the much-disputed claims for fossils in martian meteorites, the controversy has rehabilitated the idea of panspermia: that life can spread between planets.

Second, astrobiology is almost a trademarked term. The Nasa Astrobiology Institute is a virtual campus linking research centres with universities, all devoted to learning more about the general principles governing the origin of life in the universe. Significantly, Nature magazine recently looked at astrobiology in all its forms, from the quest to understand how life began on Earth to the prospects of finding intelligent life elsewhere in the universe.

Not that this should be a cause for wide-eyed celebration, say its critics. Ironically, the most vociferous of these come not from the world of science but from science fiction. Brian Aldiss, veteran writer, critic, and leading light of the genre, dismisses our current obsession with life elsewhere, however much it is justified by science, as an expensively scratched itch.

Aliens, he argues, are a manifestation of a fundamental human urge to populate the universe with ‘others’, whether gods, ghosts, little green men, or cartoon characters. Scientists should beware of taking science fiction too seriously: aliens are useful as plot devices, but this does not make them real.

A rather different criticism comes from scientists-turned-science fiction writers Jack Cohen and Ian Stewart. Both are academics - Cohen is a biologist, Stewart is a mathematician - but they have worked in SF, most recently on their novel Wheelers. Their argument with astrobiology is not that aliens might not exist, but that we cannot help be constrained in our search.

All organisms on Earth, from the tiniest bacterium to the biggest whales, are constructed according to the same rules. Earthly genetic information is carried in genes made of DNA, earthly life is based on polymers of carbon, and its chemistry happens in liquid water. Because this kind of life is all we know, we tend to think that the same rules need apply everywhere. So, when probes land on Mars, or scientists look at martian meteorites, they tend to look for the kinds of vital signs that betray earthly organisms when we have absolutely no reason for thinking that life elsewhere should be earthlike, or that our definition of life cannot be based more broadly. When the Mars Rover sat and stared at a rock, how do we know that the rock was not staring right back?

It is a fairly simple matter to come up with a definition of life that is based on what it does, rather than what it is made of. It is much more difficult, however, to make such a definition stick, preventing the term from becoming so inclusive as to be meaningless.

You might start by positing three rules. The first is that life requires the existence of information that can be reproduced and inherited, with variation. Second, that living systems seem to create order and structure and maintain it in the face of chaos. Third, that a living system has to work hard to maintain its structure, and as soon as it stops doing this it degenerates.

These rules seem, at first, to be fairly precise, in as much they weed out quietly observant martian surface rocks. But as Cohen and Stewart show in their novel, it is possible to imagine entities that follow all three rules and which appear to be alive, but which bear absolutely no resemblance to terrestrial organisms. In Wheelers, they describe civilizations of floating, methane-breathing balloons in the atmosphere of Jupiter and organisms made of magnetically-confined plasma, living in the outer layers of the sun.

Other science fiction writers have imagined life on the surfaces of neutron stars, inside computers, or even in interstellar space. In his latest novel, Look to Windward, lain M Banks describes organisms the size of continents, supporting entire civilizations as their intestinal parasites. All could be said to constitute life, but in Dr McCoy’s immortal phrase from Star Trek, ‘not as we know it’.

Could this mean that astrobiology, the aims of which are universal, is really no more than a parochial exercise? We might never know - perhaps even when we are visited by aliens from the other side of the galaxy who try, frantically, to gain our attention, by waving under our noses whatever it is they wave under such circumstances. It will not be their fault that they will be microscopic and destroyed by a single sneeze. As Cohen and Stewart conclude in Wheelers'. ‘Life goes on everywhere.’

Complete the summary below. Choose the answers from the box. There are more choices than spaces, so you will not need to use all of them.

location	principles	previous	frequently	galaxy
narrow	discussing	defining	rarely	size
never	composition	planet	extending	breakthrough
definition	mistake	regulations	basing

defining never composition planet narrow size mistake

The same biological and chemical principles determine the make-up of all terrestrial life forms, whatever their . We often assume that this is the case throughout the universe, as we have observed other kinds of organism. Scientists therefore make the of searching for indications of Earth-style living things when examining material from another , where the nature of any life may lie far outside their own definition. On the other hand, if the focus is not on but on behaviour, there is a risk of life much too broadly.

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